Civi/Api4/Query/Api4SelectQuery.php

   1 <?php
   2 /*
   3  +--------------------------------------------------------------------+
   4  | Copyright CiviCRM LLC. All rights reserved.                        |
   5  |                                                                    |
   6  | This work is published under the GNU AGPLv3 license with some      |
   7  | permitted exceptions and without any warranty. For full license    |
   8  | and copyright information, see https://civicrm.org/licensing       |
   9  +--------------------------------------------------------------------+
  10  */
  11
  12 namespace Civi\Api4\Query;
  13
  14 use Civi\Api4\Service\Schema\Joinable\CustomGroupJoinable;
  15 use Civi\Api4\Utils\FormattingUtil;
  16 use Civi\Api4\Utils\CoreUtil;
  17 use Civi\Api4\Utils\SelectUtil;
  18
  19 /**
  20  * A query `node` may be in one of three formats:
  21  *
  22  * * leaf: [$fieldName, $operator, $criteria]
  23  * * negated: ['NOT', $node]
  24  * * branch: ['OR|NOT', [$node, $node, ...]]
  25  *
  26  * Leaf operators are one of:
  27  *
  28  * * '=', '<=', '>=', '>', '<', 'LIKE', "<>", "!=",
  29  * * "NOT LIKE", 'IN', 'NOT IN', 'BETWEEN', 'NOT BETWEEN',
  30  * * 'IS NOT NULL', or 'IS NULL'.
  31  */
  32 class Api4SelectQuery {
  33
  34   const
  35     MAIN_TABLE_ALIAS = 'a',
  36     UNLIMITED = '18446744073709551615';
  37
  38   /**
  39    * @var \CRM_Utils_SQL_Select
  40    */
  41   protected $query;
  42
  43   /**
  44    * @var array
  45    */
  46   protected $joins = [];
  47
  48   /**
  49    * @var array[]
  50    */
  51   protected $apiFieldSpec;
  52
  53   /**
  54    * @var array
  55    */
  56   protected $entityFieldNames = [];
  57
  58   /**
  59    * @var array
  60    */
  61   protected $aclFields = [];
  62
  63   /**
  64    * @var \Civi\Api4\Generic\DAOGetAction
  65    */
  66   private $api;
  67
  68   /**
  69    * @var array
  70    * [alias => expr][]
  71    */
  72   protected $selectAliases = [];
  73
  74   /**
  75    * @var bool
  76    */
  77   public $forceSelectId = TRUE;
  78
  79   /**
  80    * @param \Civi\Api4\Generic\DAOGetAction $apiGet
  81    */
  82   public function __construct($apiGet) {
  83     $this->api = $apiGet;
  84
  85     // Always select ID of main table unless grouping by something else
  86     $this->forceSelectId = !$this->getGroupBy() || $this->getGroupBy() === ['id'];
  87
  88     // Build field lists
  89     foreach ($this->api->entityFields() as $field) {
  90       $this->entityFieldNames[] = $field['name'];
  91       $field['sql_name'] = '`' . self::MAIN_TABLE_ALIAS . '`.`' . $field['column_name'] . '`';
  92       $this->addSpecField($field['name'], $field);
  93     }
  94
  95     $tableName = CoreUtil::getTableName($this->getEntity());
  96     $this->query = \CRM_Utils_SQL_Select::from($tableName . ' ' . self::MAIN_TABLE_ALIAS);
  97
  98     // Add ACLs first to avoid redundant subclauses
  99     $baoName = CoreUtil::getBAOFromApiName($this->getEntity());
 100     $this->query->where($this->getAclClause(self::MAIN_TABLE_ALIAS, $baoName));
 101   }
 102
 103   /**
 104    * Builds main final sql statement after initialization.
 105    *
 106    * @return string
 107    * @throws \API_Exception
 108    * @throws \CRM_Core_Exception
 109    */
 110   public function getSql() {
 111     // Add explicit joins. Other joins implied by dot notation may be added later
 112     $this->addExplicitJoins();
 113     $this->buildSelectClause();
 114     $this->buildWhereClause();
 115     $this->buildOrderBy();
 116     $this->buildLimit();
 117     $this->buildGroupBy();
 118     $this->buildHavingClause();
 119     return $this->query->toSQL();
 120   }
 121
 122   /**
 123    * Why walk when you can
 124    *
 125    * @return array
 126    */
 127   public function run() {
 128     $results = [];
 129     $sql = $this->getSql();
 130     $this->debug('sql', $sql);
 131     $query = \CRM_Core_DAO::executeQuery($sql);
 132     while ($query->fetch()) {
 133       $result = [];
 134       foreach ($this->selectAliases as $alias => $expr) {
 135         $returnName = $alias;
 136         $alias = str_replace('.', '_', $alias);
 137         $result[$returnName] = property_exists($query, $alias) ? $query->$alias : NULL;
 138       }
 139       $results[] = $result;
 140     }
 141     FormattingUtil::formatOutputValues($results, $this->apiFieldSpec, $this->getEntity());
 142     return $results;
 143   }
 144
 145   /**
 146    * @return int
 147    * @throws \API_Exception
 148    */
 149   public function getCount() {
 150     $this->addExplicitJoins();
 151     $this->buildWhereClause();
 152     // If no having or groupBy, we only need to select count
 153     if (!$this->getHaving() && !$this->getGroupBy()) {
 154       $this->query->select('COUNT(*) AS `c`');
 155       $sql = $this->query->toSQL();
 156     }
 157     // Use a subquery to count groups from GROUP BY or results filtered by HAVING
 158     else {
 159       // With no HAVING, just select the last field grouped by
 160       if (!$this->getHaving()) {
 161         $select = array_slice($this->getGroupBy(), -1);
 162       }
 163       $this->buildSelectClause($select ?? NULL);
 164       $this->buildHavingClause();
 165       $this->buildGroupBy();
 166       $subquery = $this->query->toSQL();
 167       $sql = "SELECT count(*) AS `c` FROM ( $subquery ) AS rows";
 168     }
 169     $this->debug('sql', $sql);
 170     return (int) \CRM_Core_DAO::singleValueQuery($sql);
 171   }
 172
 173   /**
 174    * @param array $select
 175    *   Array of select expressions; defaults to $this->getSelect
 176    * @throws \API_Exception
 177    */
 178   protected function buildSelectClause($select = NULL) {
 179     // Use default if select not provided, exclude row_count which is handled elsewhere
 180     $select = array_diff($select ?? $this->getSelect(), ['row_count']);
 181     // An empty select is the same as *
 182     if (empty($select)) {
 183       $select = $this->entityFieldNames;
 184     }
 185     else {
 186       if ($this->forceSelectId) {
 187         $select = array_merge(['id'], $select);
 188       }
 189
 190       // Expand the superstar 'custom.*' to select all fields in all custom groups
 191       $customStar = array_search('custom.*', array_values($select), TRUE);
 192       if ($customStar !== FALSE) {
 193         $customGroups = civicrm_api4($this->getEntity(), 'getFields', [
 194           'checkPermissions' => FALSE,
 195           'where' => [['custom_group', 'IS NOT NULL']],
 196         ], ['custom_group' => 'custom_group']);
 197         $customSelect = [];
 198         foreach ($customGroups as $groupName) {
 199           $customSelect[] = "$groupName.*";
 200         }
 201         array_splice($select, $customStar, 1, $customSelect);
 202       }
 203
 204       // Expand wildcards in joins (the api wrapper already expanded non-joined wildcards)
 205       $wildFields = array_filter($select, function($item) {
 206         return strpos($item, '*') !== FALSE && strpos($item, '.') !== FALSE && strpos($item, '(') === FALSE && strpos($item, ' ') === FALSE;
 207       });
 208
 209       foreach ($wildFields as $item) {
 210         $pos = array_search($item, array_values($select));
 211         $this->autoJoinFK($item);
 212         $matches = SelectUtil::getMatchingFields($item, array_keys($this->apiFieldSpec));
 213         array_splice($select, $pos, 1, $matches);
 214       }
 215       $select = array_unique($select);
 216     }
 217     foreach ($select as $item) {
 218       $expr = SqlExpression::convert($item, TRUE);
 219       $valid = TRUE;
 220       foreach ($expr->getFields() as $fieldName) {
 221         $field = $this->getField($fieldName);
 222         // Remove expressions with unknown fields without raising an error
 223         if (!$field) {
 224           $select = array_diff($select, [$item]);
 225           $this->debug('undefined_fields', $fieldName);
 226           $valid = FALSE;
 227         }
 228       }
 229       if ($valid) {
 230         $alias = $expr->getAlias();
 231         if ($alias != $expr->getExpr() && isset($this->apiFieldSpec[$alias])) {
 232           throw new \API_Exception('Cannot use existing field name as alias');
 233         }
 234         $this->selectAliases[$alias] = $expr->getExpr();
 235         $this->query->select($expr->render($this->apiFieldSpec) . " AS `$alias`");
 236       }
 237     }
 238   }
 239
 240   /**
 241    * Add WHERE clause to query
 242    */
 243   protected function buildWhereClause() {
 244     foreach ($this->getWhere() as $clause) {
 245       $sql = $this->treeWalkClauses($clause, 'WHERE');
 246       if ($sql) {
 247         $this->query->where($sql);
 248       }
 249     }
 250   }
 251
 252   /**
 253    * Add HAVING clause to query
 254    *
 255    * Every expression referenced must also be in the SELECT clause.
 256    */
 257   protected function buildHavingClause() {
 258     foreach ($this->getHaving() as $clause) {
 259       $this->query->having($this->treeWalkClauses($clause, 'HAVING'));
 260     }
 261   }
 262
 263   /**
 264    * Add ORDER BY to query
 265    */
 266   protected function buildOrderBy() {
 267     foreach ($this->getOrderBy() as $item => $dir) {
 268       if ($dir !== 'ASC' && $dir !== 'DESC') {
 269         throw new \API_Exception("Invalid sort direction. Cannot order by $item $dir");
 270       }
 271       $expr = $this->getExpression($item);
 272       $column = $expr->render($this->apiFieldSpec);
 273
 274       // Use FIELD() function to sort on pseudoconstant values
 275       $suffix = strstr($item, ':');
 276       if ($suffix && $expr->getType() === 'SqlField') {
 277         $field = $this->getField($item);
 278         $options = FormattingUtil::getPseudoconstantList($field['entity'], $field['name'], substr($suffix, 1));
 279         if ($options) {
 280           asort($options);
 281           $column = "FIELD($column,'" . implode("','", array_keys($options)) . "')";
 282         }
 283       }
 284       $this->query->orderBy("$column $dir");
 285     }
 286   }
 287
 288   /**
 289    * Add LIMIT to query
 290    *
 291    * @throws \CRM_Core_Exception
 292    */
 293   protected function buildLimit() {
 294     if ($this->getLimit() || $this->getOffset()) {
 295       // If limit is 0, mysql will actually return 0 results. Instead set to maximum possible.
 296       $this->query->limit($this->getLimit() ?: self::UNLIMITED, $this->getOffset());
 297     }
 298   }
 299
 300   /**
 301    * Add GROUP BY clause to query
 302    */
 303   protected function buildGroupBy() {
 304     foreach ($this->getGroupBy() as $item) {
 305       $this->query->groupBy($this->getExpression($item)->render($this->apiFieldSpec));
 306     }
 307   }
 308
 309   /**
 310    * Recursively validate and transform a branch or leaf clause array to SQL.
 311    *
 312    * @param array $clause
 313    * @param string $type
 314    *   WHERE|HAVING|ON
 315    * @return string SQL where clause
 316    *
 317    * @throws \API_Exception
 318    * @uses composeClause() to generate the SQL etc.
 319    */
 320   protected function treeWalkClauses($clause, $type) {
 321     // Skip empty leaf.
 322     if (in_array($clause[0], ['AND', 'OR', 'NOT']) && empty($clause[1])) {
 323       return '';
 324     }
 325     switch ($clause[0]) {
 326       case 'OR':
 327       case 'AND':
 328         // handle branches
 329         if (count($clause[1]) === 1) {
 330           // a single set so AND|OR is immaterial
 331           return $this->treeWalkClauses($clause[1][0], $type);
 332         }
 333         else {
 334           $sql_subclauses = [];
 335           foreach ($clause[1] as $subclause) {
 336             $sql_subclauses[] = $this->treeWalkClauses($subclause, $type);
 337           }
 338           return '(' . implode("\n" . $clause[0], $sql_subclauses) . ')';
 339         }
 340
 341       case 'NOT':
 342         // If we get a group of clauses with no operator, assume AND
 343         if (!is_string($clause[1][0])) {
 344           $clause[1] = ['AND', $clause[1]];
 345         }
 346         return 'NOT (' . $this->treeWalkClauses($clause[1], $type) . ')';
 347
 348       default:
 349         return $this->composeClause($clause, $type);
 350     }
 351   }
 352
 353   /**
 354    * Validate and transform a leaf clause array to SQL.
 355    * @param array $clause [$fieldName, $operator, $criteria]
 356    * @param string $type
 357    *   WHERE|HAVING|ON
 358    * @return string SQL
 359    * @throws \API_Exception
 360    * @throws \Exception
 361    */
 362   protected function composeClause(array $clause, string $type) {
 363     // Pad array for unary operators
 364     list($expr, $operator, $value) = array_pad($clause, 3, NULL);
 365     if (!in_array($operator, \CRM_Core_DAO::acceptedSQLOperators(), TRUE)) {
 366       throw new \API_Exception('Illegal operator');
 367     }
 368
 369     // For WHERE clause, expr must be the name of a field.
 370     if ($type === 'WHERE') {
 371       $field = $this->getField($expr, TRUE);
 372       FormattingUtil::formatInputValue($value, $expr, $field);
 373       $fieldAlias = $field['sql_name'];
 374     }
 375     // For HAVING, expr must be an item in the SELECT clause
 376     elseif ($type === 'HAVING') {
 377       // Expr references a fieldName or alias
 378       if (isset($this->selectAliases[$expr])) {
 379         $fieldAlias = $expr;
 380         // Attempt to format if this is a real field
 381         if (isset($this->apiFieldSpec[$expr])) {
 382           FormattingUtil::formatInputValue($value, $expr, $this->apiFieldSpec[$expr]);
 383         }
 384       }
 385       // Expr references a non-field expression like a function; convert to alias
 386       elseif (in_array($expr, $this->selectAliases)) {
 387         $fieldAlias = array_search($expr, $this->selectAliases);
 388       }
 389       // If either the having or select field contains a pseudoconstant suffix, match and perform substitution
 390       else {
 391         list($fieldName) = explode(':', $expr);
 392         foreach ($this->selectAliases as $selectAlias => $selectExpr) {
 393           list($selectField) = explode(':', $selectAlias);
 394           if ($selectAlias === $selectExpr && $fieldName === $selectField && isset($this->apiFieldSpec[$fieldName])) {
 395             FormattingUtil::formatInputValue($value, $expr, $this->apiFieldSpec[$fieldName]);
 396             $fieldAlias = $selectAlias;
 397             break;
 398           }
 399         }
 400       }
 401       if (!isset($fieldAlias)) {
 402         throw new \API_Exception("Invalid expression in HAVING clause: '$expr'. Must use a value from SELECT clause.");
 403       }
 404       $fieldAlias = '`' . $fieldAlias . '`';
 405     }
 406     elseif ($type === 'ON') {
 407       $expr = $this->getExpression($expr);
 408       $fieldName = count($expr->getFields()) === 1 ? $expr->getFields()[0] : NULL;
 409       $fieldAlias = $expr->render($this->apiFieldSpec);
 410       if (is_string($value)) {
 411         $valExpr = $this->getExpression($value);
 412         if ($fieldName && $valExpr->getType() === 'SqlString') {
 413           FormattingUtil::formatInputValue($valExpr->expr, $fieldName, $this->apiFieldSpec[$fieldName]);
 414         }
 415         return sprintf('%s %s %s', $fieldAlias, $operator, $valExpr->render($this->apiFieldSpec));
 416       }
 417       elseif ($fieldName) {
 418         FormattingUtil::formatInputValue($value, $fieldName, $this->apiFieldSpec[$fieldName]);
 419       }
 420     }
 421
 422     $sql_clause = \CRM_Core_DAO::createSQLFilter($fieldAlias, [$operator => $value]);
 423     if ($sql_clause === NULL) {
 424       throw new \API_Exception("Invalid value in $type clause for '$expr'");
 425     }
 426     return $sql_clause;
 427   }
 428
 429   /**
 430    * @param string $expr
 431    * @return SqlExpression
 432    * @throws \API_Exception
 433    */
 434   protected function getExpression(string $expr) {
 435     $sqlExpr = SqlExpression::convert($expr);
 436     foreach ($sqlExpr->getFields() as $fieldName) {
 437       $this->getField($fieldName, TRUE);
 438     }
 439     return $sqlExpr;
 440   }
 441
 442   /**
 443    * Get acl clause for an entity
 444    *
 445    * @param string $tableAlias
 446    * @param \CRM_Core_DAO|string $baoName
 447    * @param array $stack
 448    * @return array
 449    */
 450   public function getAclClause($tableAlias, $baoName, $stack = []) {
 451     if (!$this->getCheckPermissions()) {
 452       return [];
 453     }
 454     // Prevent (most) redundant acl sub clauses if they have already been applied to the main entity.
 455     // FIXME: Currently this only works 1 level deep, but tracking through multiple joins would increase complexity
 456     // and just doing it for the first join takes care of most acl clause deduping.
 457     if (count($stack) === 1 && in_array($stack[0], $this->aclFields, TRUE)) {
 458       return [];
 459     }
 460     $clauses = $baoName::getSelectWhereClause($tableAlias);
 461     if (!$stack) {
 462       // Track field clauses added to the main entity
 463       $this->aclFields = array_keys($clauses);
 464     }
 465     return array_filter($clauses);
 466   }
 467
 468   /**
 469    * Fetch a field from the getFields list
 470    *
 471    * @param string $expr
 472    * @param bool $strict
 473    *   In strict mode, this will throw an exception if the field doesn't exist
 474    *
 475    * @return array|null
 476    * @throws \API_Exception
 477    */
 478   public function getField($expr, $strict = FALSE) {
 479     // If the expression contains a pseudoconstant filter like activity_type_id:label,
 480     // strip it to look up the base field name, then add the field:filter key to apiFieldSpec
 481     $col = strpos($expr, ':');
 482     $fieldName = $col ? substr($expr, 0, $col) : $expr;
 483     // Perform join if field not yet available - this will add it to apiFieldSpec
 484     if (!isset($this->apiFieldSpec[$fieldName]) && strpos($fieldName, '.')) {
 485       $this->autoJoinFK($fieldName);
 486     }
 487     $field = $this->apiFieldSpec[$fieldName] ?? NULL;
 488     if ($strict && !$field) {
 489       throw new \API_Exception("Invalid field '$fieldName'");
 490     }
 491     $this->apiFieldSpec[$expr] = $field;
 492     return $field;
 493   }
 494
 495   /**
 496    * Join onto other entities as specified by the api call.
 497    *
 498    * @throws \API_Exception
 499    * @throws \Civi\API\Exception\NotImplementedException
 500    */
 501   private function addExplicitJoins() {
 502     foreach ($this->getJoin() as $join) {
 503       // First item in the array is the entity name
 504       $entity = array_shift($join);
 505       // Which might contain an alias. Split on the keyword "AS"
 506       list($entity, $alias) = array_pad(explode(' AS ', $entity), 2, NULL);
 507       // Ensure alias is a safe string, and supply default if not given
 508       $alias = $alias ? \CRM_Utils_String::munge($alias) : strtolower($entity);
 509       // First item in the array is a boolean indicating if the join is required (aka INNER or LEFT).
 510       // The rest are join conditions.
 511       $side = array_shift($join) ? 'INNER' : 'LEFT';
 512       // Add all fields from joined entity to spec
 513       $joinEntityGet = \Civi\API\Request::create($entity, 'get', ['version' => 4, 'checkPermissions' => $this->getCheckPermissions()]);
 514       foreach ($joinEntityGet->entityFields() as $field) {
 515         $field['sql_name'] = '`' . $alias . '`.`' . $field['column_name'] . '`';
 516         $this->addSpecField($alias . '.' . $field['name'], $field);
 517       }
 518       if (!empty($join[0]) && is_string($join[0]) && \CRM_Utils_Rule::alphanumeric($join[0])) {
 519         $conditions = $this->getBridgeJoin($join, $entity, $alias);
 520       }
 521       else {
 522         $conditions = $this->getJoinConditions($join, $entity, $alias);
 523       }
 524       foreach (array_filter($join) as $clause) {
 525         $conditions[] = $this->treeWalkClauses($clause, 'ON');
 526       }
 527       $tableName = CoreUtil::getTableName($entity);
 528       $this->join($side, $tableName, $alias, $conditions);
 529     }
 530   }
 531
 532   /**
 533    * Supply conditions for an explicit join.
 534    *
 535    * @param array $joinTree
 536    * @param string $joinEntity
 537    * @param string $alias
 538    * @return array
 539    */
 540   private function getJoinConditions($joinTree, $joinEntity, $alias) {
 541     $conditions = [];
 542     // getAclClause() expects a stack of 1-to-1 join fields to help it dedupe, but this is more flexible,
 543     // so unless this is a direct 1-to-1 join with the main entity, we'll just hack it
 544     // with a padded empty stack to bypass its deduping.
 545     $stack = [NULL, NULL];
 546     // If we're not explicitly referencing the joinEntity ID in the ON clause, search for a default
 547     $explicitId = array_filter($joinTree, function($clause) use ($alias) {
 548       list($sideA, $op, $sideB) = array_pad((array) $clause, 3, NULL);
 549       return $op === '=' && ($sideA === "$alias.id" || $sideB === "$alias.id");
 550     });
 551     if (!$explicitId) {
 552       foreach ($this->apiFieldSpec as $name => $field) {
 553         if ($field['entity'] !== $joinEntity && $field['fk_entity'] === $joinEntity) {
 554           $conditions[] = $this->treeWalkClauses([$name, '=', "$alias.id"], 'ON');
 555         }
 556         elseif (strpos($name, "$alias.") === 0 && substr_count($name, '.') === 1 && $field['fk_entity'] === $this->getEntity()) {
 557           $conditions[] = $this->treeWalkClauses([$name, '=', 'id'], 'ON');
 558           $stack = ['id'];
 559         }
 560       }
 561       // Hmm, if we came up with > 1 condition, then it's ambiguous how it should be joined so we won't return anything but the generic ACLs
 562       if (count($conditions) > 1) {
 563         $stack = [NULL, NULL];
 564         $conditions = [];
 565       }
 566     }
 567     $baoName = CoreUtil::getBAOFromApiName($joinEntity);
 568     $acls = array_values($this->getAclClause($alias, $baoName, $stack));
 569     return array_merge($acls, $conditions);
 570   }
 571
 572   /**
 573    * Join onto a BridgeEntity table
 574    *
 575    * @param array $joinTree
 576    * @param string $joinEntity
 577    * @param string $alias
 578    * @return array
 579    * @throws \API_Exception
 580    */
 581   protected function getBridgeJoin(&$joinTree, $joinEntity, $alias) {
 582     $bridgeEntity = array_shift($joinTree);
 583     if (!is_a('\Civi\Api4\\' . $bridgeEntity, '\Civi\Api4\Generic\BridgeEntity', TRUE)) {
 584       throw new \API_Exception("Illegal bridge entity specified: " . $bridgeEntity);
 585     }
 586     $bridgeAlias = $alias . '_via_' . strtolower($bridgeEntity);
 587     $bridgeTable = CoreUtil::getTableName($bridgeEntity);
 588     $joinTable = CoreUtil::getTableName($joinEntity);
 589     $bridgeEntityGet = \Civi\API\Request::create($bridgeEntity, 'get', ['version' => 4, 'checkPermissions' => $this->getCheckPermissions()]);
 590     $fkToJoinField = $fkToBaseField = NULL;
 591     // Find the bridge field that links to the joinEntity (either an explicit FK or an entity_id/entity_table combo)
 592     foreach ($bridgeEntityGet->entityFields() as $name => $field) {
 593       if ($field['fk_entity'] === $joinEntity || (!$fkToJoinField && $name === 'entity_id')) {
 594         $fkToJoinField = $name;
 595       }
 596     }
 597     // Get list of entities allowed for entity_table
 598     if (array_key_exists('entity_id', $bridgeEntityGet->entityFields())) {
 599       $entityTables = (array) civicrm_api4($bridgeEntity, 'getFields', [
 600         'checkPermissions' => FALSE,
 601         'where' => [['name', '=', 'entity_table']],
 602         'loadOptions' => TRUE,
 603       ], ['options'])->first();
 604     }
 605     // If bridge field to joinEntity is entity_id, validate entity_table is allowed
 606     if (!$fkToJoinField || ($fkToJoinField === 'entity_id' && !array_key_exists($joinTable, $entityTables))) {
 607       throw new \API_Exception("Unable to join $bridgeEntity to $joinEntity");
 608     }
 609     // Create link between bridge entity and join entity
 610     $joinConditions = [
 611       "`$bridgeAlias`.`$fkToJoinField` = `$alias`.`id`",
 612     ];
 613     if ($fkToJoinField === 'entity_id') {
 614       $joinConditions[] = "`$bridgeAlias`.`entity_table` = '$joinTable'";
 615     }
 616     // Register fields from the bridge entity as if they belong to the join entity
 617     foreach ($bridgeEntityGet->entityFields() as $name => $field) {
 618       if ($name == 'id' || $name == $fkToJoinField || ($name == 'entity_table' && $fkToJoinField == 'entity_id')) {
 619         continue;
 620       }
 621       if ($field['fk_entity'] || (!$fkToBaseField && $name == 'entity_id')) {
 622         $fkToBaseField = $name;
 623       }
 624       // Note these fields get a sql alias pointing to the bridge entity, but an api alias pretending they belong to the join entity
 625       $field['sql_name'] = '`' . $bridgeAlias . '`.`' . $field['column_name'] . '`';
 626       $this->addSpecField($alias . '.' . $field['name'], $field);
 627     }
 628     // Move conditions for the bridge join out of the joinTree
 629     $bridgeConditions = [];
 630     $joinTree = array_filter($joinTree, function($clause) use ($fkToBaseField, $alias, $bridgeAlias, &$bridgeConditions) {
 631       list($sideA, $op, $sideB) = array_pad((array) $clause, 3, NULL);
 632       if ($op === '=' && $sideB && ($sideA === "$alias.$fkToBaseField" || $sideB === "$alias.$fkToBaseField")) {
 633         $expr = $sideA === "$alias.$fkToBaseField" ? $sideB : $sideA;
 634         $bridgeConditions[] = "`$bridgeAlias`.`$fkToBaseField` = " . $this->getExpression($expr)->render($this->apiFieldSpec);
 635         return FALSE;
 636       }
 637       elseif ($op === '=' && $fkToBaseField == 'entity_id' && ($sideA === "$alias.entity_table" || $sideB === "$alias.entity_table")) {
 638         $expr = $sideA === "$alias.entity_table" ? $sideB : $sideA;
 639         $bridgeConditions[] = "`$bridgeAlias`.`entity_table` = " . $this->getExpression($expr)->render($this->apiFieldSpec);
 640         return FALSE;
 641       }
 642       return TRUE;
 643     });
 644     // If no bridge conditions were specified, link it to the base entity
 645     if (!$bridgeConditions) {
 646       $bridgeConditions[] = "`$bridgeAlias`.`$fkToBaseField` = a.id";
 647       if ($fkToBaseField == 'entity_id') {
 648         if (!array_key_exists($this->getFrom(), $entityTables)) {
 649           throw new \API_Exception("Unable to join $bridgeEntity to " . $this->getEntity());
 650         }
 651         $bridgeConditions[] = "`$bridgeAlias`.`entity_table` = '" . $this->getFrom() . "'";
 652       }
 653     }
 654
 655     $this->join('LEFT', $bridgeTable, $bridgeAlias, $bridgeConditions);
 656
 657     $baoName = CoreUtil::getBAOFromApiName($joinEntity);
 658     $acls = array_values($this->getAclClause($alias, $baoName, [NULL, NULL]));
 659     return array_merge($acls, $joinConditions);
 660   }
 661
 662   /**
 663    * Joins a path and adds all fields in the joined entity to apiFieldSpec
 664    *
 665    * @param $key
 666    * @throws \API_Exception
 667    * @throws \Exception
 668    */
 669   protected function autoJoinFK($key) {
 670     if (isset($this->apiFieldSpec[$key])) {
 671       return;
 672     }
 673
 674     $pathArray = explode('.', $key);
 675
 676     /** @var \Civi\Api4\Service\Schema\Joiner $joiner */
 677     $joiner = \Civi::container()->get('joiner');
 678     // The last item in the path is the field name. We don't care about that; we'll add all fields from the joined entity.
 679     array_pop($pathArray);
 680     $pathString = implode('.', $pathArray);
 681
 682     if (!$joiner->canAutoJoin($this->getFrom(), $pathString)) {
 683       return;
 684     }
 685
 686     $joinPath = $joiner->join($this, $pathString);
 687
 688     $lastLink = array_pop($joinPath);
 689
 690     // Custom field names are already prefixed
 691     $isCustom = $lastLink instanceof CustomGroupJoinable;
 692     if ($isCustom) {
 693       array_pop($pathArray);
 694     }
 695     $prefix = $pathArray ? implode('.', $pathArray) . '.' : '';
 696     // Cache field info for retrieval by $this->getField()
 697     foreach ($lastLink->getEntityFields() as $fieldObject) {
 698       $fieldArray = $fieldObject->toArray();
 699       $fieldArray['sql_name'] = '`' . $lastLink->getAlias() . '`.`' . $fieldArray['column_name'] . '`';
 700       $this->addSpecField($prefix . $fieldArray['name'], $fieldArray);
 701     }
 702   }
 703
 704   /**
 705    * @param string $side
 706    * @param string $tableName
 707    * @param string $tableAlias
 708    * @param array $conditions
 709    */
 710   public function join($side, $tableName, $tableAlias, $conditions) {
 711     // INNER JOINs take precedence over LEFT JOINs
 712     if ($side != 'LEFT' || !isset($this->joins[$tableAlias])) {
 713       $this->joins[$tableAlias] = $side;
 714       $this->query->join($tableAlias, "$side JOIN `$tableName` `$tableAlias` ON " . implode(' AND ', $conditions));
 715     }
 716   }
 717
 718   /**
 719    * @return FALSE|string
 720    */
 721   public function getFrom() {
 722     return CoreUtil::getTableName($this->getEntity());
 723   }
 724
 725   /**
 726    * @return string
 727    */
 728   public function getEntity() {
 729     return $this->api->getEntityName();
 730   }
 731
 732   /**
 733    * @return array
 734    */
 735   public function getSelect() {
 736     return $this->api->getSelect();
 737   }
 738
 739   /**
 740    * @return array
 741    */
 742   public function getWhere() {
 743     return $this->api->getWhere();
 744   }
 745
 746   /**
 747    * @return array
 748    */
 749   public function getHaving() {
 750     return $this->api->getHaving();
 751   }
 752
 753   /**
 754    * @return array
 755    */
 756   public function getJoin() {
 757     return $this->api->getJoin();
 758   }
 759
 760   /**
 761    * @return array
 762    */
 763   public function getGroupBy() {
 764     return $this->api->getGroupBy();
 765   }
 766
 767   /**
 768    * @return array
 769    */
 770   public function getOrderBy() {
 771     return $this->api->getOrderBy();
 772   }
 773
 774   /**
 775    * @return mixed
 776    */
 777   public function getLimit() {
 778     return $this->api->getLimit();
 779   }
 780
 781   /**
 782    * @return mixed
 783    */
 784   public function getOffset() {
 785     return $this->api->getOffset();
 786   }
 787
 788   /**
 789    * @return \CRM_Utils_SQL_Select
 790    */
 791   public function getQuery() {
 792     return $this->query;
 793   }
 794
 795   /**
 796    * @return bool|string
 797    */
 798   public function getCheckPermissions() {
 799     return $this->api->getCheckPermissions();
 800   }
 801
 802   /**
 803    * @param string $path
 804    * @param array $field
 805    */
 806   private function addSpecField($path, $field) {
 807     // Only add field to spec if we have permission
 808     if ($this->getCheckPermissions() && !empty($field['permission']) && !\CRM_Core_Permission::check($field['permission'])) {
 809       $this->apiFieldSpec[$path] = FALSE;
 810       return;
 811     }
 812     $this->apiFieldSpec[$path] = $field;
 813   }
 814
 815   /**
 816    * Add something to the api's debug output if debugging is enabled
 817    *
 818    * @param $key
 819    * @param $item
 820    */
 821   public function debug($key, $item) {
 822     if ($this->api->getDebug()) {
 823       $this->api->_debugOutput[$key][] = $item;
 824     }
 825   }
 826
 827 }