<?php
/**
* @file
* Database schema code for PostgreSQL database servers.
*/
/**
* @ingroup schemaapi
* @{
*/
class DatabaseSchema_pgsql extends DatabaseSchema {
/**
* PostgreSQL's temporary namespace name.
*
* @var string
*/
protected $tempNamespaceName;
/**
* A cache of information about blob columns and sequences of tables.
*
* This is collected by DatabaseConnection_pgsql->queryTableInformation(),
* by introspecting the database.
*
* @see DatabaseConnection_pgsql->queryTableInformation()
* @var array
*/
protected $tableInformation = array();
/**
* The maximum allowed length for index, primary key and constraint names.
*
* Value will usually be set to a 63 chars limit but PostgreSQL allows
* to higher this value before compiling, so we need to check for that.
*
* @var int
*/
protected $maxIdentifierLength;
/**
* Make sure to limit identifiers according to PostgreSQL compiled in length.
*
* PostgreSQL allows in standard configuration identifiers no longer than 63
* chars for table/relation names, indexes, primary keys, and constraints. So
* we map all identifiers that are too long to drupal_base64hash_tag, where
* tag is one of:
* - idx for indexes
* - key for constraints
* - pkey for primary keys
* - seq for sequences
*
* @param string $table_identifier_part
* The first argument used to build the identifier string. This usually
* refers to a table/relation name.
* @param string $column_identifier_part
* The second argument used to build the identifier string. This usually
* refers to one or more column names.
* @param string $tag
* The identifier tag. It can be one of 'idx', 'key', 'pkey' or 'seq'.
*
* @return string
* The index/constraint/pkey identifier.
*/
protected function ensureIdentifiersLength($table_identifier_part, $column_identifier_part, $tag) {
$info = $this->getPrefixInfo($table_identifier_part);
$table_identifier_part = $info['table'];
// Filters out potentially empty $column_identifier_part to ensure
// compatibility with old naming convention (see prefixNonTable()).
$identifiers = array_filter(array($table_identifier_part, $column_identifier_part, $tag));
$identifierName = implode('_', $identifiers);
// Retrieve the max identifier length which is usually 63 characters
// but can be altered before PostgreSQL is compiled so we need to check.
if (empty($this->maxIdentifierLength)) {
$this->maxIdentifierLength = $this->connection->query("SHOW max_identifier_length")->fetchField();
}
if (strlen($identifierName) > $this->maxIdentifierLength) {
$saveIdentifier = 'drupal_' . $this->hashBase64($identifierName) . '_' . $tag;
}
else {
$saveIdentifier = $identifierName;
}
return $saveIdentifier;
}
/**
* Fetch the list of blobs and sequences used on a table.
*
* We introspect the database to collect the information required by insert
* and update queries.
*
* @param $table_name
* The non-prefixed name of the table.
* @return
* An object with two member variables:
* - 'blob_fields' that lists all the blob fields in the table.
* - 'sequences' that lists the sequences used in that table.
*/
public function queryTableInformation($table) {
// Generate a key to reference this table's information on.
$key = $this->connection->prefixTables('{' . $table . '}');
// Take into account that temporary tables are stored in a different schema.
// \DatabaseConnection::generateTemporaryTableName() sets 'db_temporary_'
// prefix to all temporary tables.
if (strpos($key, '.') === FALSE && strpos($table, 'db_temporary_') === FALSE) {
$key = 'public.' . $key;
}
else {
$key = $this->getTempNamespaceName() . '.' . $key;
}
if (!isset($this->tableInformation[$key])) {
$table_information = (object) array(
'blob_fields' => array(),
'sequences' => array(),
);
// The bytea columns and sequences for a table can be found in
// pg_attribute, which is significantly faster than querying the
// information_schema. The data type of a field can be found by lookup
// of the attribute ID, and the default value must be extracted from the
// node tree for the attribute definition instead of the historical
// human-readable column, adsrc.
$sql = <<<'EOD'
SELECT pg_attribute.attname AS column_name, format_type(pg_attribute.atttypid, pg_attribute.atttypmod) AS data_type, pg_get_expr(pg_attrdef.adbin, pg_attribute.attrelid) AS column_default
FROM pg_attribute
LEFT JOIN pg_attrdef ON pg_attrdef.adrelid = pg_attribute.attrelid AND pg_attrdef.adnum = pg_attribute.attnum
WHERE pg_attribute.attnum > 0
AND NOT pg_attribute.attisdropped
AND pg_attribute.attrelid = :key::regclass
AND (format_type(pg_attribute.atttypid, pg_attribute.atttypmod) = 'bytea'
OR pg_get_expr(pg_attrdef.adbin, pg_attribute.attrelid) LIKE 'nextval%')
EOD;
$result = $this->connection->query($sql, array(
':key' => $key,
));
if (empty($result)) {
return $table_information;
}
foreach ($result as $column) {
if ($column->data_type == 'bytea') {
$table_information->blob_fields[$column->column_name] = TRUE;
}
elseif (preg_match("/nextval\('([^']+)'/", $column->column_default, $matches)) {
// We must know of any sequences in the table structure to help us
// return the last insert id. If there is more than 1 sequences the
// first one (index 0 of the sequences array) will be used.
$table_information->sequences[] = $matches[1];
$table_information->serial_fields[] = $column->column_name;
}
}
$this->tableInformation[$key] = $table_information;
}
return $this->tableInformation[$key];
}
/**
* Gets PostgreSQL's temporary namespace name.
*
* @return string
* PostgreSQL's temporary namespace anme.
*/
protected function getTempNamespaceName() {
if (!isset($this->tempNamespaceName)) {
$this->tempNamespaceName = $this->connection->query('SELECT nspname FROM pg_namespace WHERE oid = pg_my_temp_schema()')->fetchField();
}
return $this->tempNamespaceName;
}
/**
* Fetch the list of CHECK constraints used on a field.
*
* We introspect the database to collect the information required by field
* alteration.
*
* @param $table
* The non-prefixed name of the table.
* @param $field
* The name of the field.
* @return
* An array of all the checks for the field.
*/
public function queryFieldInformation($table, $field) {
$prefixInfo = $this->getPrefixInfo($table, TRUE);
// Split the key into schema and table for querying.
$schema = $prefixInfo['schema'];
$table_name = $prefixInfo['table'];
$field_information = (object) array(
'checks' => array(),
);
$checks = $this->connection->query("SELECT conname FROM pg_class cl INNER JOIN pg_constraint co ON co.conrelid = cl.oid INNER JOIN pg_attribute attr ON attr.attrelid = cl.oid AND attr.attnum = ANY (co.conkey) INNER JOIN pg_namespace ns ON cl.relnamespace = ns.oid WHERE co.contype = 'c' AND ns.nspname = :schema AND cl.relname = :table AND attr.attname = :column", array(
':schema' => $schema,
':table' => $table_name,
':column' => $field,
));
$field_information = $checks->fetchCol();
return $field_information;
}
/**
* Generate SQL to create a new table from a Drupal schema definition.
*
* @param $name
* The name of the table to create.
* @param $table
* A Schema API table definition array.
* @return
* An array of SQL statements to create the table.
*/
protected function createTableSql($name, $table) {
$sql_fields = array();
foreach ($table['fields'] as $field_name => $field) {
$sql_fields[] = $this->createFieldSql($field_name, $this->processField($field));
}
$sql_keys = array();
if (isset($table['primary key']) && is_array($table['primary key'])) {
$sql_keys[] = 'CONSTRAINT ' . $this->ensureIdentifiersLength($name, '', 'pkey') . ' PRIMARY KEY (' . implode(', ', $table['primary key']) . ')';
}
if (isset($table['unique keys']) && is_array($table['unique keys'])) {
foreach ($table['unique keys'] as $key_name => $key) {
$sql_keys[] = 'CONSTRAINT ' . $this->ensureIdentifiersLength($name, $key_name, 'key') . ' UNIQUE (' . implode(', ', $key) . ')';
}
}
$sql = "CREATE TABLE {" . $name . "} (\n\t";
$sql .= implode(",\n\t", $sql_fields);
if (count($sql_keys) > 0) {
$sql .= ",\n\t";
}
$sql .= implode(",\n\t", $sql_keys);
$sql .= "\n)";
$statements[] = $sql;
if (isset($table['indexes']) && is_array($table['indexes'])) {
foreach ($table['indexes'] as $key_name => $key) {
$statements[] = $this->_createIndexSql($name, $key_name, $key);
}
}
// Add table comment.
if (!empty($table['description'])) {
$statements[] = 'COMMENT ON TABLE {' . $name . '} IS ' . $this->prepareComment($table['description']);
}
// Add column comments.
foreach ($table['fields'] as $field_name => $field) {
if (!empty($field['description'])) {
$statements[] = 'COMMENT ON COLUMN {' . $name . '}.' . $field_name . ' IS ' . $this->prepareComment($field['description']);
}
}
return $statements;
}
/**
* Create an SQL string for a field to be used in table creation or
* alteration.
*
* Before passing a field out of a schema definition into this
* function it has to be processed by _db_process_field().
*
* @param $name
* Name of the field.
* @param $spec
* The field specification, as per the schema data structure format.
*/
protected function createFieldSql($name, $spec) {
$sql = $name . ' ' . $spec['pgsql_type'];
if (isset($spec['type']) && $spec['type'] == 'serial') {
unset($spec['not null']);
}
if (in_array($spec['pgsql_type'], array('varchar', 'character', 'text')) && isset($spec['length'])) {
$sql .= '(' . $spec['length'] . ')';
}
elseif (isset($spec['precision']) && isset($spec['scale'])) {
$sql .= '(' . $spec['precision'] . ', ' . $spec['scale'] . ')';
}
if (!empty($spec['unsigned'])) {
$sql .= " CHECK ($name >= 0)";
}
if (isset($spec['not null'])) {
if ($spec['not null']) {
$sql .= ' NOT NULL';
}
else {
$sql .= ' NULL';
}
}
if (isset($spec['default'])) {
$default = is_string($spec['default']) ? "'" . $spec['default'] . "'" : $spec['default'];
$sql .= " default $default";
}
return $sql;
}
/**
* Set database-engine specific properties for a field.
*
* @param $field
* A field description array, as specified in the schema documentation.
*/
protected function processField($field) {
if (!isset($field['size'])) {
$field['size'] = 'normal';
}
// Set the correct database-engine specific datatype.
// In case one is already provided, force it to lowercase.
if (isset($field['pgsql_type'])) {
$field['pgsql_type'] = drupal_strtolower($field['pgsql_type']);
}
else {
$map = $this->getFieldTypeMap();
$field['pgsql_type'] = $map[$field['type'] . ':' . $field['size']];
}
if (!empty($field['unsigned'])) {
// Unsigned datatypes are not supported in PostgreSQL 8.3. In MySQL,
// they are used to ensure a positive number is inserted and it also
// doubles the maximum integer size that can be stored in a field.
// The PostgreSQL schema in Drupal creates a check constraint
// to ensure that a value inserted is >= 0. To provide the extra
// integer capacity, here, we bump up the column field size.
if (!isset($map)) {
$map = $this->getFieldTypeMap();
}
switch ($field['pgsql_type']) {
case 'smallint':
$field['pgsql_type'] = $map['int:medium'];
break;
case 'int' :
$field['pgsql_type'] = $map['int:big'];
break;
}
}
if (isset($field['type']) && $field['type'] == 'serial') {
unset($field['not null']);
}
return $field;
}
/**
* This maps a generic data type in combination with its data size
* to the engine-specific data type.
*/
function getFieldTypeMap() {
// Put :normal last so it gets preserved by array_flip. This makes
// it much easier for modules (such as schema.module) to map
// database types back into schema types.
// $map does not use drupal_static as its value never changes.
static $map = array(
'varchar:normal' => 'varchar',
'char:normal' => 'character',
'text:tiny' => 'text',
'text:small' => 'text',
'text:medium' => 'text',
'text:big' => 'text',
'text:normal' => 'text',
'int:tiny' => 'smallint',
'int:small' => 'smallint',
'int:medium' => 'int',
'int:big' => 'bigint',
'int:normal' => 'int',
'float:tiny' => 'real',
'float:small' => 'real',
'float:medium' => 'real',
'float:big' => 'double precision',
'float:normal' => 'real',
'numeric:normal' => 'numeric',
'blob:big' => 'bytea',
'blob:normal' => 'bytea',
'serial:tiny' => 'serial',
'serial:small' => 'serial',
'serial:medium' => 'serial',
'serial:big' => 'bigserial',
'serial:normal' => 'serial',
);
return $map;
}
protected function _createKeySql($fields) {
$return = array();
foreach ($fields as $field) {
if (is_array($field)) {
$return[] = 'substr(' . $field[0] . ', 1, ' . $field[1] . ')';
}
else {
$return[] = '"' . $field . '"';
}
}
return implode(', ', $return);
}
/**
* {@inheritdoc}
*/
public function tableExists($table) {
// In PostgreSQL "unquoted names are always folded to lower case."
// @see DatabaseSchema_pgsql::buildTableNameCondition().
$prefixInfo = $this->getPrefixInfo(strtolower($table), TRUE);
return (bool) $this->connection->query("SELECT 1 FROM pg_tables WHERE schemaname = :schema AND tablename = :table", array(':schema' => $prefixInfo['schema'], ':table' => $prefixInfo['table']))->fetchField();
}
/**
* {@inheritdoc}
*/
public function findTables($table_expression) {
$individually_prefixed_tables = $this->connection->getUnprefixedTablesMap();
$default_prefix = $this->connection->tablePrefix();
$default_prefix_length = strlen($default_prefix);
$tables = array();
// Load all the tables up front in order to take into account per-table
// prefixes. The actual matching is done at the bottom of the method.
$results = $this->connection->query("SELECT tablename FROM pg_tables WHERE schemaname = :schema", array(':schema' => $this->defaultSchema));
foreach ($results as $table) {
// Take into account tables that have an individual prefix.
if (isset($individually_prefixed_tables[$table->tablename])) {
$prefix_length = strlen($this->connection->tablePrefix($individually_prefixed_tables[$table->tablename]));
}
elseif ($default_prefix && substr($table->tablename, 0, $default_prefix_length) !== $default_prefix) {
// This table name does not start the default prefix, which means that
// it is not managed by Drupal so it should be excluded from the result.
continue;
}
else {
$prefix_length = $default_prefix_length;
}
// Remove the prefix from the returned tables.
$unprefixed_table_name = substr($table->tablename, $prefix_length);
// The pattern can match a table which is the same as the prefix. That
// will become an empty string when we remove the prefix, which will
// probably surprise the caller, besides not being a prefixed table. So
// remove it.
if (!empty($unprefixed_table_name)) {
$tables[$unprefixed_table_name] = $unprefixed_table_name;
}
}
// Need to use strtolower on the table name as it was used previously by
// DatabaseSchema_pgsql::buildTableNameCondition().
// @see https://www.drupal.org/project/drupal/issues/3262341
$table_expression = strtolower($table_expression);
// Convert the table expression from its SQL LIKE syntax to a regular
// expression and escape the delimiter that will be used for matching.
$table_expression = str_replace(array('%', '_'), array('.*?', '.'), preg_quote($table_expression, '/'));
$tables = preg_grep('/^' . $table_expression . '$/i', $tables);
return $tables;
}
function renameTable($table, $new_name) {
if (!$this->tableExists($table)) {
throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot rename @table to @table_new: table @table doesn't exist.", array('@table' => $table, '@table_new' => $new_name)));
}
if ($this->tableExists($new_name)) {
throw new DatabaseSchemaObjectExistsException(t("Cannot rename @table to @table_new: table @table_new already exists.", array('@table' => $table, '@table_new' => $new_name)));
}
// Get the schema and tablename for the old table.
$old_full_name = $this->connection->prefixTables('{' . $table . '}');
list($old_schema, $old_table_name) = strpos($old_full_name, '.') ? explode('.', $old_full_name) : array('public', $old_full_name);
// Index names and constraint names are global in PostgreSQL, so we need to
// rename them when renaming the table.
$indexes = $this->connection->query('SELECT indexname FROM pg_indexes WHERE schemaname = :schema AND tablename = :table', array(':schema' => $old_schema, ':table' => $old_table_name));
foreach ($indexes as $index) {
// Get the index type by suffix, e.g. idx/key/pkey
$index_type = substr($index->indexname, strrpos($index->indexname, '_') + 1);
// If the index is already rewritten by ensureIdentifiersLength() to not
// exceed the 63 chars limit of PostgreSQL, we need to take care of that.
// Example (drupal_Gk7Su_T1jcBHVuvSPeP22_I3Ni4GrVEgTYlIYnBJkro_idx).
if (strpos($index->indexname, 'drupal_') !== FALSE) {
preg_match('/^drupal_(.*)_' . preg_quote($index_type) . '/', $index->indexname, $matches);
$index_name = $matches[1];
}
else {
if ($index_type == 'pkey') {
// Primary keys do not have a specific name in D7.
$index_name = '';
}
else {
// Make sure to remove the suffix from index names, because
// ensureIdentifiersLength() will add the suffix again and thus
// would result in a wrong index name.
preg_match('/^' . preg_quote($old_full_name) . '_(.*)_' . preg_quote($index_type) . '/', $index->indexname, $matches);
$index_name = $matches[1];
}
}
$this->connection->query('ALTER INDEX ' . $index->indexname . ' RENAME TO ' . $this->ensureIdentifiersLength($new_name, $index_name, $index_type));
}
// Now rename the table.
// Ensure the new table name does not include schema syntax.
$prefixInfo = $this->getPrefixInfo($new_name);
$this->connection->query('ALTER TABLE {' . $table . '} RENAME TO ' . $prefixInfo['table']);
}
public function dropTable($table) {
if (!$this->tableExists($table)) {
return FALSE;
}
$this->connection->query('DROP TABLE {' . $table . '}');
return TRUE;
}
public function addField($table, $field, $spec, $new_keys = array()) {
if (!$this->tableExists($table)) {
throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add field @table.@field: table doesn't exist.", array('@field' => $field, '@table' => $table)));
}
if ($this->fieldExists($table, $field)) {
throw new DatabaseSchemaObjectExistsException(t("Cannot add field @table.@field: field already exists.", array('@field' => $field, '@table' => $table)));
}
$fixnull = FALSE;
if (!empty($spec['not null']) && !isset($spec['default'])) {
$fixnull = TRUE;
$spec['not null'] = FALSE;
}
$query = 'ALTER TABLE {' . $table . '} ADD COLUMN ';
$query .= $this->createFieldSql($field, $this->processField($spec));
$this->connection->query($query);
if (isset($spec['initial'])) {
$this->connection->update($table)
->fields(array($field => $spec['initial']))
->execute();
}
if ($fixnull) {
$this->connection->query("ALTER TABLE {" . $table . "} ALTER $field SET NOT NULL");
}
if (isset($new_keys)) {
$this->_createKeys($table, $new_keys);
}
// Add column comment.
if (!empty($spec['description'])) {
$this->connection->query('COMMENT ON COLUMN {' . $table . '}.' . $field . ' IS ' . $this->prepareComment($spec['description']));
}
}
public function dropField($table, $field) {
if (!$this->fieldExists($table, $field)) {
return FALSE;
}
$this->connection->query('ALTER TABLE {' . $table . '} DROP COLUMN "' . $field . '"');
return TRUE;
}
public function fieldSetDefault($table, $field, $default) {
if (!$this->fieldExists($table, $field)) {
throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot set default value of field @table.@field: field doesn't exist.", array('@table' => $table, '@field' => $field)));
}
if (!isset($default)) {
$default = 'NULL';
}
else {
$default = is_string($default) ? "'$default'" : $default;
}
$this->connection->query('ALTER TABLE {' . $table . '} ALTER COLUMN "' . $field . '" SET DEFAULT ' . $default);
}
public function fieldSetNoDefault($table, $field) {
if (!$this->fieldExists($table, $field)) {
throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot remove default value of field @table.@field: field doesn't exist.", array('@table' => $table, '@field' => $field)));
}
$this->connection->query('ALTER TABLE {' . $table . '} ALTER COLUMN "' . $field . '" DROP DEFAULT');
}
/**
* {@inheritdoc}
*/
public function fieldExists($table, $column) {
// In PostgreSQL "unquoted names are always folded to lower case."
// @see DatabaseSchema_pgsql::buildTableNameCondition().
$prefixInfo = $this->getPrefixInfo(strtolower($table));
return (bool) $this->connection->query("SELECT 1 FROM pg_attribute WHERE attrelid = :key::regclass AND attname = :column AND NOT attisdropped AND attnum > 0", array(':key' => $prefixInfo['schema'] . '.' . $prefixInfo['table'], ':column' => $column))->fetchField();
}
public function indexExists($table, $name) {
// Details https://www.postgresql.org/docs/10/view-pg-indexes.html
$index_name = $this->ensureIdentifiersLength($table, $name, 'idx');
return (bool) $this->connection->query("SELECT 1 FROM pg_indexes WHERE indexname = '$index_name'")->fetchField();
}
/**
* Helper function: check if a constraint (PK, FK, UK) exists.
*
* @param $table
* The name of the table.
* @param $name
* The name of the constraint (typically 'pkey' or '[constraint]_key').
*/
protected function constraintExists($table, $name) {
// ensureIdentifiersLength() expects three parameters, thus we split our
// constraint name in a proper name and a suffix.
if ($name == 'pkey') {
$suffix = $name;
$name = '';
}
else {
$pos = strrpos($name, '_');
$suffix = substr($name, $pos + 1);
$name = substr($name, 0, $pos);
}
$constraint_name = $this->ensureIdentifiersLength($table, $name, $suffix);
return (bool) $this->connection->query("SELECT 1 FROM pg_constraint WHERE conname = '$constraint_name'")->fetchField();
}
public function addPrimaryKey($table, $fields) {
if (!$this->tableExists($table)) {
throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add primary key to table @table: table doesn't exist.", array('@table' => $table)));
}
if ($this->constraintExists($table, 'pkey')) {
throw new DatabaseSchemaObjectExistsException(t("Cannot add primary key to table @table: primary key already exists.", array('@table' => $table)));
}
$this->connection->query('ALTER TABLE {' . $table . '} ADD CONSTRAINT ' . $this->ensureIdentifiersLength($table, '', 'pkey') . ' PRIMARY KEY (' . implode(',', $fields) . ')');
}
public function dropPrimaryKey($table) {
if (!$this->constraintExists($table, 'pkey')) {
return FALSE;
}
$this->connection->query('ALTER TABLE {' . $table . '} DROP CONSTRAINT ' . $this->ensureIdentifiersLength($table, '', 'pkey'));
return TRUE;
}
function addUniqueKey($table, $name, $fields) {
if (!$this->tableExists($table)) {
throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add unique key @name to table @table: table doesn't exist.", array('@table' => $table, '@name' => $name)));
}
if ($this->constraintExists($table, $name . '_key')) {
throw new DatabaseSchemaObjectExistsException(t("Cannot add unique key @name to table @table: unique key already exists.", array('@table' => $table, '@name' => $name)));
}
$this->connection->query('ALTER TABLE {' . $table . '} ADD CONSTRAINT "' . $this->ensureIdentifiersLength($table, $name, 'key') . '" UNIQUE (' . implode(',', $fields) . ')');
}
public function dropUniqueKey($table, $name) {
if (!$this->constraintExists($table, $name . '_key')) {
return FALSE;
}
$this->connection->query('ALTER TABLE {' . $table . '} DROP CONSTRAINT "' . $this->ensureIdentifiersLength($table, $name, 'key') . '"');
return TRUE;
}
public function addIndex($table, $name, $fields) {
if (!$this->tableExists($table)) {
throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add index @name to table @table: table doesn't exist.", array('@table' => $table, '@name' => $name)));
}
if ($this->indexExists($table, $name)) {
throw new DatabaseSchemaObjectExistsException(t("Cannot add index @name to table @table: index already exists.", array('@table' => $table, '@name' => $name)));
}
$this->connection->query($this->_createIndexSql($table, $name, $fields));
}
public function dropIndex($table, $name) {
if (!$this->indexExists($table, $name)) {
return FALSE;
}
$this->connection->query('DROP INDEX ' . $this->ensureIdentifiersLength($table, $name, 'idx'));
return TRUE;
}
public function changeField($table, $field, $field_new, $spec, $new_keys = array()) {
if (!$this->fieldExists($table, $field)) {
throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot change the definition of field @table.@name: field doesn't exist.", array('@table' => $table, '@name' => $field)));
}
if (($field != $field_new) && $this->fieldExists($table, $field_new)) {
throw new DatabaseSchemaObjectExistsException(t("Cannot rename field @table.@name to @name_new: target field already exists.", array('@table' => $table, '@name' => $field, '@name_new' => $field_new)));
}
$spec = $this->processField($spec);
// We need to typecast the new column to best be able to transfer the data
// Schema_pgsql::getFieldTypeMap() will return possibilities that are not
// 'cast-able' such as 'serial' - so they need to be casted int instead.
if (in_array($spec['pgsql_type'], array('serial', 'bigserial', 'numeric'))) {
$typecast = 'int';
}
else {
$typecast = $spec['pgsql_type'];
}
if (in_array($spec['pgsql_type'], array('varchar', 'character', 'text')) && isset($spec['length'])) {
$typecast .= '(' . $spec['length'] . ')';
}
elseif (isset($spec['precision']) && isset($spec['scale'])) {
$typecast .= '(' . $spec['precision'] . ', ' . $spec['scale'] . ')';
}
// Remove old check constraints.
$field_info = $this->queryFieldInformation($table, $field);
foreach ($field_info as $check) {
$this->connection->query('ALTER TABLE {' . $table . '} DROP CONSTRAINT "' . $check . '"');
}
// Remove old default.
$this->fieldSetNoDefault($table, $field);
$this->connection->query('ALTER TABLE {' . $table . '} ALTER "' . $field . '" TYPE ' . $typecast . ' USING "' . $field . '"::' . $typecast);
if (isset($spec['not null'])) {
if ($spec['not null']) {
$nullaction = 'SET NOT NULL';
}
else {
$nullaction = 'DROP NOT NULL';
}
$this->connection->query('ALTER TABLE {' . $table . '} ALTER "' . $field . '" ' . $nullaction);
}
if (in_array($spec['pgsql_type'], array('serial', 'bigserial'))) {
// Type "serial" is known to PostgreSQL, but *only* during table creation,
// not when altering. Because of that, the sequence needs to be created
// and initialized by hand.
$seq = "{" . $table . "}_" . $field_new . "_seq";
$this->connection->query("CREATE SEQUENCE " . $seq);
// Set sequence to maximal field value to not conflict with existing
// entries.
$this->connection->query("SELECT setval('" . $seq . "', MAX(\"" . $field . '")) FROM {' . $table . "}");
$this->connection->query('ALTER TABLE {' . $table . '} ALTER "' . $field . '" SET DEFAULT nextval(\'' . $seq . '\')');
}
// Rename the column if necessary.
if ($field != $field_new) {
$this->connection->query('ALTER TABLE {' . $table . '} RENAME "' . $field . '" TO "' . $field_new . '"');
}
// Add unsigned check if necessary.
if (!empty($spec['unsigned'])) {
$this->connection->query('ALTER TABLE {' . $table . '} ADD CHECK ("' . $field_new . '" >= 0)');
}
// Add default if necessary.
if (isset($spec['default'])) {
$this->fieldSetDefault($table, $field_new, $spec['default']);
}
// Change description if necessary.
if (!empty($spec['description'])) {
$this->connection->query('COMMENT ON COLUMN {' . $table . '}."' . $field_new . '" IS ' . $this->prepareComment($spec['description']));
}
if (isset($new_keys)) {
$this->_createKeys($table, $new_keys);
}
}
protected function _createIndexSql($table, $name, $fields) {
$query = 'CREATE INDEX "' . $this->ensureIdentifiersLength($table, $name, 'idx') . '" ON {' . $table . '} (';
$query .= $this->_createKeySql($fields) . ')';
return $query;
}
protected function _createKeys($table, $new_keys) {
if (isset($new_keys['primary key'])) {
$this->addPrimaryKey($table, $new_keys['primary key']);
}
if (isset($new_keys['unique keys'])) {
foreach ($new_keys['unique keys'] as $name => $fields) {
$this->addUniqueKey($table, $name, $fields);
}
}
if (isset($new_keys['indexes'])) {
foreach ($new_keys['indexes'] as $name => $fields) {
$this->addIndex($table, $name, $fields);
}
}
}
/**
* Retrieve a table or column comment.
*/
public function getComment($table, $column = NULL) {
$info = $this->getPrefixInfo($table);
// Don't use {} around pg_class, pg_attribute tables.
if (isset($column)) {
return $this->connection->query('SELECT col_description(oid, attnum) FROM pg_class, pg_attribute WHERE attrelid = oid AND relname = ? AND attname = ?', array($info['table'], $column))->fetchField();
}
else {
return $this->connection->query('SELECT obj_description(oid, ?) FROM pg_class WHERE relname = ?', array('pg_class', $info['table']))->fetchField();
}
}
/**
* Calculates a base-64 encoded, PostgreSQL-safe sha-256 hash per PostgreSQL
* documentation: 4.1. Lexical Structure.
*
* @param $data
* String to be hashed.
*
* @return string
* A base-64 encoded sha-256 hash, with + and / replaced with _ and any =
* padding characters removed.
*/
protected function hashBase64($data) {
// Ensure lowercase as D7's pgsql driver does not quote identifiers
// consistently, and they are therefore folded to lowercase by PostgreSQL.
$hash = strtolower(base64_encode(hash('sha256', $data, TRUE)));
// Modify the hash so it's safe to use in PostgreSQL identifiers.
return strtr($hash, array('+' => '_', '/' => '_', '=' => ''));
}
/**
* Build a condition to match a table name against a standard information_schema.
*
* In PostgreSQL "unquoted names are always folded to lower case." The pgsql
* driver does not quote table names, so they are therefore always lowercase.
*
* @see https://www.postgresql.org/docs/14/sql-syntax-lexical.html
*/
protected function buildTableNameCondition($table_name, $operator = '=', $add_prefix = TRUE) {
return parent::buildTableNameCondition(strtolower($table_name), $operator, $add_prefix);
}
}