PgsqlSchema.php

<?php

namespace Intersvyaz\ExtendedDb;

use CDbException;
use CDbSchema;
use CDbTableSchema;
use CException;
use CPgsqlColumnSchema;
use CPgsqlCommandBuilder;
use CPgsqlTableSchema;

/**
 * IsPgsqlSchema is the class for retrieving metadata information from a PostgreSQL database.
 * From Postgres version >= 12
 * @see \CPgsqlSchema
 */
class PgsqlSchema extends CDbSchema
{
    const DEFAULT_SCHEMA = 'public';

    /**
     * @var array the abstract column types mapped to physical column types.
     * @since 1.1.6
     */
    public $columnTypes = array(
        'pk' => 'serial NOT NULL PRIMARY KEY',
        'bigpk' => 'bigserial NOT NULL PRIMARY KEY',
        'string' => 'character varying (255)',
        'text' => 'text',
        'integer' => 'integer',
        'bigint' => 'bigint',
        'float' => 'double precision',
        'decimal' => 'numeric',
        'datetime' => 'timestamp',
        'timestamp' => 'timestamp',
        'time' => 'time',
        'date' => 'date',
        'binary' => 'bytea',
        'boolean' => 'boolean',
        'money' => 'decimal(19,4)',
    );

    private $_sequences = array();

    /**
     * Quotes a table name for use in a query.
     * A simple table name does not schema prefix.
     * @param string $name table name
     * @return string the properly quoted table name
     * @since 1.1.6
     */
    public function quoteSimpleTableName($name)
    {
        return '"' . $name . '"';
    }

    /**
     * Resets the sequence value of a table's primary key.
     * The sequence will be reset such that the primary key of the next new row inserted
     * will have the specified value or max value of a primary key plus one (i.e. sequence trimming).
     * @param CDbTableSchema $table the table schema whose primary key sequence will be reset
     * @param integer|null $value the value for the primary key of the next new row inserted.
     * If this is not set, the next new row's primary key will have the max value of a primary
     * key plus one (i.e. sequence trimming).
     * @throws CDbException
     * @since 1.1
     */
    public function resetSequence($table, $value = null)
    {
        if ($table->sequenceName === null)
            return;
        $sequence = '"' . $table->sequenceName . '"';
        if (strpos($sequence, '.') !== false)
            $sequence = str_replace('.', '"."', $sequence);
        if ($value !== null)
            $value = (int)$value;
        else
            $value = "(SELECT COALESCE(MAX(\"{$table->primaryKey}\"),0) FROM {$table->rawName})+1";
        $this->getDbConnection()
            ->createCommand("SELECT SETVAL('$sequence',$value,false)")
            ->execute();
    }

    /**
     * Enables or disables integrity check.
     * @param boolean $check whether to turn on or off the integrity check.
     * @param string $schema the schema of the tables. Defaults to empty string, meaning the current or default schema.
     * @throws CDbException
     * @since 1.1
     */
    public function checkIntegrity($check = true, $schema = '')
    {
        $enable = $check ? 'ENABLE' : 'DISABLE';
        $tableNames = $this->getTableNames($schema);
        $db = $this->getDbConnection();
        foreach ($tableNames as $tableName) {
            $tableName = '"' . $tableName . '"';
            if (strpos($tableName, '.') !== false)
                $tableName = str_replace('.', '"."', $tableName);
            $db->createCommand("ALTER TABLE $tableName $enable TRIGGER ALL")->execute();
        }
    }

    /**
     * Loads the metadata for the specified table.
     * @param string $name table name
     * @return CDbTableSchema driver dependent table metadata.
     * @throws CException
     */
    protected function loadTable($name)
    {
        $table = new CPgsqlTableSchema;
        $this->resolveTableNames($table, $name);
        if (!$this->findColumns($table))
            return null;
        $this->findConstraints($table);

        if (is_string($table->primaryKey) && isset($this->_sequences[$table->rawName . '.' . $table->primaryKey]))
            $table->sequenceName = $this->_sequences[$table->rawName . '.' . $table->primaryKey];
        elseif (is_array($table->primaryKey)) {
            foreach ($table->primaryKey as $pk) {
                if (isset($this->_sequences[$table->rawName . '.' . $pk])) {
                    $table->sequenceName = $this->_sequences[$table->rawName . '.' . $pk];
                    break;
                }
            }
        }

        return $table;
    }

    /**
     * Generates various kinds of table names.
     * @param CPgsqlTableSchema $table the table instance
     * @param string $name the unquoted table name
     */
    protected function resolveTableNames($table, $name)
    {
        $parts = explode('.', str_replace('"', '', $name));
        if (isset($parts[1])) {
            $schemaName = $parts[0];
            $tableName = $parts[1];
        } else {
            $schemaName = self::DEFAULT_SCHEMA;
            $tableName = $parts[0];
        }

        $table->name = $tableName;
        $table->schemaName = $schemaName;
        if ($schemaName === self::DEFAULT_SCHEMA)
            $table->rawName = $this->quoteTableName($tableName);
        else
            $table->rawName = $this->quoteTableName($schemaName) . '.' . $this->quoteTableName($tableName);
    }

    /**
     * Collects the table column metadata.
     * @param CPgsqlTableSchema $table the table metadata
     * @return boolean whether the table exists in the database
     * @throws CException
     */
    protected function findColumns($table)
    {
        $sql = <<<EOD
SELECT 
        a.attname, 
        LOWER(format_type(a.atttypid, a.atttypmod)) AS type, 
        pg_get_expr(d.adbin, d.adrelid) as adsrc, 
        a.attnotnull, 
        a.atthasdef,
	    pg_catalog.col_description(a.attrelid, a.attnum) AS comment
FROM pg_attribute a 
    LEFT JOIN pg_attrdef d ON a.attrelid = d.adrelid AND a.attnum = d.adnum
WHERE a.attnum > 0 AND NOT a.attisdropped
	AND a.attrelid = (SELECT oid FROM pg_catalog.pg_class WHERE relname=:table
	AND relnamespace = (SELECT oid FROM pg_catalog.pg_namespace WHERE nspname = :schema))
ORDER BY a.attnum
EOD;
        $command = $this->getDbConnection()->createCommand($sql);
        $command->bindValue(':table', $table->name);
        $command->bindValue(':schema', $table->schemaName);

        if (($columns = $command->queryAll()) === array())
            return false;

        foreach ($columns as $column) {
            $c = $this->createColumn($column);
            $table->columns[$c->name] = $c;

            if (
                stripos($column['adsrc'], 'nextval') === 0
                && preg_match('/nextval\([^\']*\'([^\']+)\'[^\)]*\)/i', $column['adsrc'], $matches)
            ) {
                if (strpos($matches[1], '.') !== false || $table->schemaName === self::DEFAULT_SCHEMA) {
                    $this->_sequences[$table->rawName . '.' . $c->name] = $matches[1];
                } else {
                    $this->_sequences[$table->rawName . '.' . $c->name] = $table->schemaName . '.' . $matches[1];
                }
                $c->autoIncrement = true;
            }
        }
        return true;
    }

    /**
     * Creates a table column.
     * @param array $column column metadata
     * @return CPgsqlColumnSchema normalized column metadata
     */
    protected function createColumn($column)
    {
        $c = new CPgsqlColumnSchema;
        $c->name = $column['attname'];
        $c->rawName = $this->quoteColumnName($c->name);
        $c->allowNull = !$column['attnotnull'];
        $c->isPrimaryKey = false;
        $c->isForeignKey = false;
        $c->comment = $column['comment'] === null ? '' : $column['comment'];

        $c->init($column['type'], $column['atthasdef'] ? $column['adsrc'] : null);

        return $c;
    }

    /**
     * Collects the primary and foreign key column details for the given table.
     * @param CPgsqlTableSchema $table the table metadata
     * @throws CException
     */
    protected function findConstraints($table)
    {
        $sql = <<<EOD
SELECT conname, consrc, contype, indkey FROM (
	SELECT
		conname,
        pg_catalog.pg_get_constraintdef(oid) AS consrc,
		contype,
		conrelid AS relid,
		NULL AS indkey
	FROM
		pg_catalog.pg_constraint
	WHERE
		contype IN ('f', 'c')
	UNION ALL
	SELECT
		pc.relname,
		NULL,
		CASE WHEN indisprimary THEN
				'p'
		ELSE
				'u'
		END,
		pi.indrelid,
		indkey
	FROM
		pg_catalog.pg_class pc,
		pg_catalog.pg_index pi
	WHERE
		pc.oid=pi.indexrelid
		AND EXISTS (
			SELECT 1 FROM pg_catalog.pg_depend d JOIN pg_catalog.pg_constraint c
			ON (d.refclassid = c.tableoid AND d.refobjid = c.oid)
			WHERE d.classid = pc.tableoid AND d.objid = pc.oid AND d.deptype = 'i' AND c.contype IN ('u', 'p')
	)
) AS sub
WHERE relid = (SELECT oid FROM pg_catalog.pg_class WHERE relname=:table
	AND relnamespace = (SELECT oid FROM pg_catalog.pg_namespace
	WHERE nspname=:schema))
EOD;
        $command = $this->getDbConnection()->createCommand($sql);
        $command->bindValue(':table', $table->name);
        $command->bindValue(':schema', $table->schemaName);
        foreach ($command->queryAll() as $row) {
            if ($row['contype'] === 'p') { // primary key
                $this->findPrimaryKey($table, $row['indkey']);
            } elseif ($row['contype'] === 'f') {// foreign key
                $this->findForeignKey($table, $row['consrc']);
            }
        }
    }

    /**
     * Collects primary key information.
     * @param CPgsqlTableSchema $table the table metadata
     * @param string $indices pgsql primary key index list
     * @throws CException
     */
    protected function findPrimaryKey($table, $indices)
    {
        $indices = implode(', ', preg_split('/\s+/', $indices));
        $sql = <<<EOD
SELECT attnum, attname FROM pg_catalog.pg_attribute WHERE
	attrelid=(
		SELECT oid FROM pg_catalog.pg_class WHERE relname=:table AND relnamespace=(
			SELECT oid FROM pg_catalog.pg_namespace WHERE nspname=:schema
		)
	)
	AND attnum IN ({$indices})
EOD;
        $command = $this->getDbConnection()->createCommand($sql);
        $command->bindValue(':table', $table->name);
        $command->bindValue(':schema', $table->schemaName);
        foreach ($command->queryAll() as $row) {
            $name = $row['attname'];
            if (isset($table->columns[$name])) {
                $table->columns[$name]->isPrimaryKey = true;
                if ($table->primaryKey === null)
                    $table->primaryKey = $name;
                elseif (is_string($table->primaryKey))
                    $table->primaryKey = array($table->primaryKey, $name);
                else
                    $table->primaryKey[] = $name;
            }
        }
    }

    /**
     * Collects foreign key information.
     * @param CPgsqlTableSchema $table the table metadata
     * @param string $src pgsql foreign key definition
     */
    protected function findForeignKey($table, $src)
    {
        $matches = array();
        $brackets = '\(([^\)]+)\)';
        $pattern = "/FOREIGN\s+KEY\s+{$brackets}\s+REFERENCES\s+([^\(]+){$brackets}/i";
        if (preg_match($pattern, str_replace('"', '', $src), $matches)) {
            $keys = preg_split('/,\s+/', $matches[1]);
            $tableName = $matches[2];
            $fkeys = preg_split('/,\s+/', $matches[3]);
            foreach ($keys as $i => $key) {
                $table->foreignKeys[$key] = array($tableName, $fkeys[$i]);
                if (isset($table->columns[$key]))
                    $table->columns[$key]->isForeignKey = true;
            }
        }
    }

    /**
     * Returns all table names in the database.
     * @param string $schema the schema of the tables. Defaults to empty string, meaning the current or default schema.
     * If not empty, the returned table names will be prefixed with the schema name.
     * @return array all table names in the database.
     * @throws CException
     */
    protected function findTableNames($schema = '')
    {
        if ($schema === '')
            $schema = self::DEFAULT_SCHEMA;
        $sql = <<<EOD
SELECT table_name, table_schema FROM information_schema.tables
WHERE table_schema=:schema AND table_type='BASE TABLE'
EOD;
        $command = $this->getDbConnection()->createCommand($sql);
        $command->bindParam(':schema', $schema);
        $rows = $command->queryAll();
        $names = array();
        foreach ($rows as $row) {
            if ($schema === self::DEFAULT_SCHEMA) {
                $names[] = $row['table_name'];
            } else {
                $names[] = $row['table_schema'] . '.' . $row['table_name'];
            }
        }
        return $names;
    }

    /**
     * Builds a SQL statement for renaming a DB table.
     * @param string $table the table to be renamed. The name will be properly quoted by the method.
     * @param string $newName the new table name. The name will be properly quoted by the method.
     * @return string the SQL statement for renaming a DB table.
     * @since 1.1.6
     */
    public function renameTable($table, $newName)
    {
        return 'ALTER TABLE ' . $this->quoteTableName($table) . ' RENAME TO ' . $this->quoteTableName($newName);
    }

    /**
     * Builds a SQL statement for adding a new DB column.
     * @param string $table the table that the new column will be added to. The table name will be properly quoted by the method.
     * @param string $column the name of the new column. The name will be properly quoted by the method.
     * @param string $type the column type. The {@link getColumnType} method will be invoked to convert abstract column type (if any)
     * into the physical one. Anything that is not recognized as abstract type will be kept in the generated SQL.
     * For example, 'string' will be turned into 'varchar(255)', while 'string not null' will become 'varchar(255) not null'.
     * @return string the SQL statement for adding a new column.
     * @since 1.1.6
     */
    public function addColumn($table, $column, $type)
    {
        $type = $this->getColumnType($type);
        $sql = 'ALTER TABLE ' . $this->quoteTableName($table)
            . ' ADD COLUMN ' . $this->quoteColumnName($column) . ' '
            . $type;
        return $sql;
    }

    /**
     * Builds a SQL statement for changing the definition of a column.
     * @param string $table the table whose column is to be changed. The table name will be properly quoted by the method.
     * @param string $column the name of the column to be changed. The name will be properly quoted by the method.
     * @param string $type the new column type. The {@link getColumnType} method will be invoked to convert abstract column type (if any)
     * into the physical one. Anything that is not recognized as abstract type will be kept in the generated SQL.
     * For example, 'string' will be turned into 'varchar(255)', while 'string not null' will become 'varchar(255) not null'.
     * @return string the SQL statement for changing the definition of a column.
     * @since 1.1.6
     */
    public function alterColumn($table, $column, $type)
    {
        $type = $this->getColumnType($type);
        $sql = 'ALTER TABLE ' . $this->quoteTableName($table) . ' ALTER COLUMN '
            . $this->quoteColumnName($column) . ' TYPE ' . $this->getColumnType($type);
        return $sql;
    }

    /**
     * Builds a SQL statement for dropping an index.
     * @param string $name the name of the index to be dropped. The name will be properly quoted by the method.
     * @param string $table the table whose index is to be dropped. The name will be properly quoted by the method.
     * @return string the SQL statement for dropping an index.
     * @since 1.1.6
     */
    public function dropIndex($name, $table)
    {
        return 'DROP INDEX ' . $this->quoteTableName($name);
    }

    /**
     * Creates a command builder for the database.
     * This method may be overridden by child classes to create a DBMS-specific command builder.
     * @return CPgsqlCommandBuilder command builder instance.
     */
    protected function createCommandBuilder()
    {
        return new CPgsqlCommandBuilder($this);
    }
}