/**
* Get database id given a user name
* @param $name \string Username
- * @return \2types{\int,\null} The corresponding user's ID, or null if user is nonexistent
- * @static
+ * @return \types{\int,\null} The corresponding user's ID, or null if user is nonexistent
*/
static function idFromName( $name ) {
$nt = Title::makeTitleSafe( NS_USER, $name );
* Given unvalidated user input, return a canonical username, or false if
* the username is invalid.
* @param $name \string User input
- * @param $validate \2types{\string,\bool} Type of validation to use:
+ * @param $validate \types{\string,\bool} Type of validation to use:
* - false No validation
* - 'valid' Valid for batch processes
* - 'usable' Valid for batch processes and login
*
* @see getNewtalk()
* @param $field \string 'user_ip' for anonymous users, 'user_id' otherwise
- * @param $id \2types{\string,\int} User's IP address for anonymous users, User ID otherwise
+ * @param $id \types{\string,\int} User's IP address for anonymous users, User ID otherwise
* @param $fromMaster \bool true to fetch from the master, false for a slave
* @return \bool True if the user has new messages
* @private
/**
* Add or update the new messages flag
* @param $field \string 'user_ip' for anonymous users, 'user_id' otherwise
- * @param $id \2types{\string,\int} User's IP address for anonymous users, User ID otherwise
+ * @param $id \types{\string,\int} User's IP address for anonymous users, User ID otherwise
* @return \bool True if successful, false otherwise
* @private
*/
/**
* Clear the new messages flag for the given user
* @param $field \string 'user_ip' for anonymous users, 'user_id' otherwise
- * @param $id \2types{\string,\int} User's IP address for anonymous users, User ID otherwise
+ * @param $id \types{\string,\int} User's IP address for anonymous users, User ID otherwise
* @return \bool True if successful, false otherwise
* @private
*/
* login credentials aren't being hijacked with a foreign form
* submission.
*
- * @param $salt \2types{\string,\arrayof{\string}} Optional function-specific data for hashing
+ * @param $salt \types{\string,\arrayof{\string}} Optional function-specific data for hashing
* @return \string The new edit token
*/
function editToken( $salt = '' ) {
* Generate a new e-mail confirmation token and send a confirmation/invalidation
* mail to the user's given address.
*
- * @return \2types{\bool,\type{WikiError}} True on success, a WikiError object on failure.
+ * @return \types{\bool,\type{WikiError}} True on success, a WikiError object on failure.
*/
function sendConfirmationMail() {
global $wgLang;
* @param $body \string Message body
* @param $from \string Optional From address; if unspecified, default $wgPasswordSender will be used
* @param $replyto \string Reply-To address
- * @return \2types{\bool,\type{WikiError}} True on success, a WikiError object on failure
+ * @return \types{\bool,\type{WikiError}} True on success, a WikiError object on failure
*/
function sendMail( $subject, $body, $from = null, $replyto = null ) {
if( is_null( $from ) ) {
/**
* Get the timestamp of account creation.
*
- * @return \2types{\string,\bool} string Timestamp of account creation, or false for
+ * @return \types{\string,\bool} string Timestamp of account creation, or false for
* non-existent/anonymous user accounts.
*/
public function getRegistration() {
* Get the title of a page describing a particular group
*
* @param $group \string Internal group name
- * @return \2types{\type{Title},\bool} Title of the page if it exists, false otherwise
+ * @return \types{\type{Title},\bool} Title of the page if it exists, false otherwise
*/
static function getGroupPage( $group ) {
global $wgMessageCache;
/**
* Return the last query that went through Database::query()
- * @return string
+ * @return String
*/
function lastQuery() { return $this->mLastQuery; }
/**
* Is a connection to the database open?
- * @return bool
+ * @return Boolean
*/
function isOpen() { return $this->mOpened; }
# Other functions
#------------------------------------------------------------------------------
- /**@{{
+ /**
* Constructor.
- * @param string $server database server host
- * @param string $user database user name
- * @param string $password database user password
- * @param string $dbname database name
- * @param failFunction
+ * @param $server String: database server host
+ * @param $user String: database user name
+ * @param $password String: database user password
+ * @param $dbName String: database name
+ * @param $failFunction
* @param $flags
* @param $tablePrefix String: database table prefixes. By default use the prefix gave in LocalSettings.php
*/
}
/**
- * @static
+ * Same as new Database( ... ), kept for backward compatibility
+ * @param $server String: database server host
+ * @param $user String: database user name
+ * @param $password String: database user password
+ * @param $dbName String: database name
* @param failFunction
* @param $flags
*/
/**
* Usually aborts on failure
* If the failFunction is set to a non-zero integer, returns success
+ * @param $server String: database server host
+ * @param $user String: database user name
+ * @param $password String: database user password
+ * @param $dbName String: database name
*/
function open( $server, $user, $password, $dbName ) {
global $wgAllDBsAreLocalhost;
wfProfileOut( __METHOD__ );
return $success;
}
- /**@}}*/
protected function installErrorHandler() {
$this->mPHPError = false;
* Closes a database connection.
* if it is open : commits any open transactions
*
- * @return bool operation success. true if already closed.
+ * @return Bool operation success. true if already closed.
*/
function close()
{
}
/**
- * @param string $error fallback error message, used if none is given by MySQL
+ * @param $error String: fallback error message, used if none is given by MySQL
*/
function reportConnectionError( $error = 'Unknown error' ) {
$myError = $this->lastError();
* @param $sql String: SQL query
* @param $fname String: Name of the calling function, for profiling/SHOW PROCESSLIST
* comment (you can use __METHOD__ or add some extra info)
- * @param $tempIgnore Bool: Whether to avoid throwing an exception on errors...
+ * @param $tempIgnore Boolean: Whether to avoid throwing an exception on errors...
* maybe best to catch the exception instead?
* @return true for a successful write query, ResultWrapper object for a successful read query,
* or false on failure if $tempIgnore set
* The DBMS-dependent part of query()
* @param $sql String: SQL query.
* @return Result object to feed to fetchObject, fetchRow, ...; or false on failure
- * @access private
+ * @private
*/
/*private*/ function doQuery( $sql ) {
if( $this->bufferResults() ) {
}
/**
- * @param $error
- * @param $errno
- * @param $sql
- * @param string $fname
- * @param bool $tempIgnore
+ * @param $error String
+ * @param $errno Integer
+ * @param $sql String
+ * @param $fname String
+ * @param $tempIgnore Boolean
*/
function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
global $wgCommandLineMode;
/**
* Execute a prepared query with the various arguments
- * @param string $prepared the prepared sql
- * @param mixed $args Either an array here, or put scalars as varargs
+ * @param $prepared String: the prepared sql
+ * @param $args Mixed: Either an array here, or put scalars as varargs
*/
function execute( $prepared, $args = null ) {
if( !is_array( $args ) ) {
/**
* Prepare & execute an SQL statement, quoting and inserting arguments
* in the appropriate places.
- * @param string $query
- * @param string $args ...
+ * @param $query String
+ * @param $args ...
*/
function safeQuery( $query, $args = null ) {
$prepared = $this->prepare( $query, 'Database::safeQuery' );
/**
* For faking prepared SQL statements on DBs that don't support
* it directly.
- * @param string $preparedSql - a 'preparable' SQL statement
- * @param array $args - array of arguments to fill it with
+ * @param $preparedQuery String: a 'preparable' SQL statement
+ * @param $args Array of arguments to fill it with
* @return string executable SQL
*/
function fillPrepared( $preparedQuery, $args ) {
* The arguments should be in $this->preparedArgs and must not be touched
* while we're doing this.
*
- * @param array $matches
- * @return string
+ * @param $matches Array
+ * @return String
* @private
*/
function fillPreparedArg( $matches ) {
}
}
- /**#@+
- * @param mixed $res A SQL result
- */
/**
* Free a result object
+ * @param $res Mixed: A SQL result
*/
function freeResult( $res ) {
if ( $res instanceof ResultWrapper ) {
/**
* Get the number of rows in a result object
+ * @param $res Mixed: A SQL result
*/
function numRows( $res ) {
if ( $res instanceof ResultWrapper ) {
/**
* Get the number of fields in a result object
* See documentation for mysql_num_fields()
+ * @param $res Mixed: A SQL result
*/
function numFields( $res ) {
if ( $res instanceof ResultWrapper ) {
* Get a field name in a result object
* See documentation for mysql_field_name():
* http://www.php.net/mysql_field_name
+ * @param $res Mixed: A SQL result
+ * @param $n Integer
*/
function fieldName( $res, $n ) {
if ( $res instanceof ResultWrapper ) {
/**
* Change the position of the cursor in a result object
* See mysql_data_seek()
+ * @param $res Mixed: A SQL result
+ * @param $row Mixed: Either MySQL row or ResultWrapper
*/
function dataSeek( $res, $row ) {
if ( $res instanceof ResultWrapper ) {
* See mysql_affected_rows() for more details
*/
function affectedRows() { return mysql_affected_rows( $this->mConn ); }
- /**#@-*/ // end of template : @param $result
/**
* Simple UPDATE wrapper
* This function exists for historical reasons, Database::update() has a more standard
* calling convention and feature set
*/
- function set( $table, $var, $value, $cond, $fname = 'Database::set' )
- {
+ function set( $table, $var, $value, $cond, $fname = 'Database::set' ) {
$table = $this->tableName( $table );
$sql = "UPDATE $table SET $var = '" .
$this->strencode( $value ) . "' WHERE ($cond)";
*
* @private
*
- * @param array $options an associative array of options to be turned into
+ * @param $options Array: associative array of options to be turned into
* an SQL query, valid keys are listed in the function.
- * @return array
+ * @return Array
*/
function makeSelectOptions( $options ) {
$preLimitTail = $postLimitTail = '';
/**
* SELECT wrapper
*
- * @param mixed $table Array or string, table name(s) (prefix auto-added)
- * @param mixed $vars Array or string, field name(s) to be retrieved
- * @param mixed $conds Array or string, condition(s) for WHERE
- * @param string $fname Calling function name (use __METHOD__) for logs/profiling
- * @param array $options Associative array of options (e.g. array('GROUP BY' => 'page_title')),
- * see Database::makeSelectOptions code for list of supported stuff
- * @param array $join_conds Associative array of table join conditions (optional)
- * (e.g. array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
+ * @param $table Mixed: Array or string, table name(s) (prefix auto-added)
+ * @param $vars Mixed: Array or string, field name(s) to be retrieved
+ * @param $conds Mixed: Array or string, condition(s) for WHERE
+ * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
+ * @param $options Array: Associative array of options (e.g. array('GROUP BY' => 'page_title')),
+ * see Database::makeSelectOptions code for list of supported stuff
+ * @param $join_conds Array: Associative array of table join conditions (optional)
+ * (e.g. array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
* @return mixed Database result resource (feed to Database::fetchObject or whatever), or false on failure
*/
function select( $table, $vars, $conds='', $fname = 'Database::select', $options = array(), $join_conds = array() )
/**
* SELECT wrapper
*
- * @param mixed $table Array or string, table name(s) (prefix auto-added)
- * @param mixed $vars Array or string, field name(s) to be retrieved
- * @param mixed $conds Array or string, condition(s) for WHERE
- * @param string $fname Calling function name (use __METHOD__) for logs/profiling
- * @param array $options Associative array of options (e.g. array('GROUP BY' => 'page_title')),
- * see Database::makeSelectOptions code for list of supported stuff
- * @param array $join_conds Associative array of table join conditions (optional)
- * (e.g. array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
+ * @param $table Mixed: Array or string, table name(s) (prefix auto-added)
+ * @param $vars Mixed: Array or string, field name(s) to be retrieved
+ * @param $conds Mixed: Array or string, condition(s) for WHERE
+ * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
+ * @param $options Array: Associative array of options (e.g. array('GROUP BY' => 'page_title')),
+ * see Database::makeSelectOptions code for list of supported stuff
+ * @param $join_conds Array: Associative array of table join conditions (optional)
+ * (e.g. array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
* @return string, the SQL text
*/
function selectSQLText( $table, $vars, $conds='', $fname = 'Database::select', $options = array(), $join_conds = array() ) {
* Single row SELECT wrapper
* Aborts or returns FALSE on error
*
- * $vars: the selected variables
- * $conds: a condition map, terms are ANDed together.
+ * @param $table String: table name
+ * @param $vars String: the selected variables
+ * @param $conds Array: a condition map, terms are ANDed together.
* Items with numeric keys are taken to be literal conditions
* Takes an array of selected variables, and a condition map, which is ANDed
* e.g: selectRow( "page", array( "page_id" ), array( "page_namespace" =>
* NS_MAIN, "page_title" => "Astronomy" ) ) would return an object where
* $obj- >page_id is the ID of the Astronomy article
+ * @param $fname String: Calling functio name
+ * @param $options Array
+ * @param $join_conds Array
*
* @todo migrate documentation to phpdocumentor format
*/
* Removes most variables from an SQL query and replaces them with X or N for numbers.
* It's only slightly flawed. Don't use for anything important.
*
- * @param string $sql A SQL Query
- * @static
+ * @param $sql String: A SQL Query
*/
static function generalizeSQL( $sql ) {
# This does the same as the regexp below would do, but in such a way
* Make UPDATE options for the Database::update function
*
* @private
- * @param array $options The options passed to Database::update
+ * @param $options Array: The options passed to Database::update
* @return string
*/
function makeUpdateOptions( $options ) {
/**
* UPDATE wrapper, takes a condition array and a SET array
*
- * @param string $table The table to UPDATE
- * @param array $values An array of values to SET
- * @param array $conds An array of conditions (WHERE). Use '*' to update all rows.
- * @param string $fname The Class::Function calling this function
- * (for the log)
- * @param array $options An array of UPDATE options, can be one or
+ * @param $table String: The table to UPDATE
+ * @param $values Array: An array of values to SET
+ * @param $conds Array: An array of conditions (WHERE). Use '*' to update all rows.
+ * @param $fname String: The Class::Function calling this function
+ * (for the log)
+ * @param $options Array: An array of UPDATE options, can be one or
* more of IGNORE, LOW_PRIORITY
- * @return bool
+ * @return Boolean
*/
function update( $table, $values, $conds, $fname = 'Database::update', $options = array() ) {
$table = $this->tableName( $table );
* themselves. Pass the canonical name to such functions. This is only needed
* when calling query() directly.
*
- * @param string $name database table name
- * @return string full database name
+ * @param $name String: database table name
+ * @return String: full database name
*/
function tableName( $name ) {
global $wgSharedDB, $wgSharedPrefix, $wgSharedTables;
/**
* Wrapper for addslashes()
- * @param string $s String to be slashed.
- * @return string slashed string.
+ * @param $s String: to be slashed.
+ * @return String: slashed string.
*/
function strencode( $s ) {
return mysql_real_escape_string( $s, $this->mConn );
*
* DO NOT put the join condition in $conds
*
- * @param string $delTable The table to delete from.
- * @param string $joinTable The other table.
- * @param string $delVar The variable to join on, in the first table.
- * @param string $joinVar The variable to join on, in the second table.
- * @param array $conds Condition array of field names mapped to variables, ANDed together in the WHERE clause
+ * @param $delTable String: The table to delete from.
+ * @param $joinTable String: The other table.
+ * @param $delVar String: The variable to join on, in the first table.
+ * @param $joinVar String: The variable to join on, in the second table.
+ * @param $conds Array: Condition array of field names mapped to variables, ANDed together in the WHERE clause
+ * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
*/
function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = 'Database::deleteJoin' ) {
if ( !$conds ) {
/**
* Construct a LIMIT query with optional offset
* This is used for query pages
- * $sql string SQL query we will append the limit too
- * $limit integer the SQL limit
- * $offset integer the SQL offset (default false)
+ * @param $sql String: SQL query we will append the limit too
+ * @param $limit Integer: the SQL limit
+ * @param $offset Integer the SQL offset (default false)
*/
function limitResult($sql, $limit, $offset=false) {
if( !is_numeric($limit) ) {
* Returns an SQL expression for a simple conditional.
* Uses IF on MySQL.
*
- * @param string $cond SQL expression which will result in a boolean value
- * @param string $trueVal SQL expression to return if true
- * @param string $falseVal SQL expression to return if false
- * @return string SQL fragment
+ * @param $cond String: SQL expression which will result in a boolean value
+ * @param $trueVal String: SQL expression to return if true
+ * @param $falseVal String: SQL expression to return if false
+ * @return String: SQL fragment
*/
function conditional( $cond, $trueVal, $falseVal ) {
return " IF($cond, $trueVal, $falseVal) ";
* Returns a comand for str_replace function in SQL query.
* Uses REPLACE() in MySQL
*
- * @param string $orig String or column to modify
- * @param string $old String or column to seek
- * @param string $new String or column to replace with
+ * @param $orig String: column to modify
+ * @param $old String: column to seek
+ * @param $new String: column to replace with
*/
function strreplace( $orig, $old, $new ) {
return "REPLACE({$orig}, {$old}, {$new})";
/**
* Do a SELECT MASTER_POS_WAIT()
*
- * @param string $file the binlog file
- * @param string $pos the binlog position
- * @param integer $timeout the maximum number of seconds to wait for synchronisation
+ * @param $pos MySQLMasterPos object
+ * @param $timeout Integer: the maximum number of seconds to wait for synchronisation
*/
function masterPosWait( MySQLMasterPos $pos, $timeout ) {
$fname = 'Database::masterPosWait';
}
/**
- * @return string wikitext of a link to the server software's web site
+ * @return String: wikitext of a link to the server software's web site
*/
function getSoftwareLink() {
return "[http://www.mysql.com/ MySQL]";
}
/**
- * @return string Version information from the database
+ * @return String: Version information from the database
*/
function getServerVersion() {
return mysql_get_server_info( $this->mConn );
* May be useful for very long batch queries such as
* full-wiki dumps, where a single query reads out
* over hours or days.
- * @param int $timeout in seconds
+ * @param $timeout Integer in seconds
*/
public function setTimeout( $timeout ) {
$this->query( "SET net_read_timeout=$timeout" );
/**
* Read and execute SQL commands from a file.
* Returns true on success, error string or exception on failure (depending on object's error ignore settings)
- * @param string $filename File name to open
- * @param callback $lineCallback Optional function called before reading each line
- * @param callback $resultCallback Optional function called for each MySQL result
+ * @param $filename String: File name to open
+ * @param $lineCallback Callback: Optional function called before reading each line
+ * @param $resultCallback Callback: Optional function called for each MySQL result
*/
function sourceFile( $filename, $lineCallback = false, $resultCallback = false ) {
$fp = fopen( $filename, 'r' );
/**
* Read and execute commands from an open file handle
* Returns true on success, error string or exception on failure (depending on object's error ignore settings)
- * @param string $fp File handle
- * @param callback $lineCallback Optional function called before reading each line
- * @param callback $resultCallback Optional function called for each MySQL result
+ * @param $fp String: File handle
+ * @param $lineCallback Callback: Optional function called before reading each line
+ * @param $resultCallback Callback: Optional function called for each MySQL result
*/
function sourceStream( $fp, $lineCallback = false, $resultCallback = false ) {
$cmd = "";
* Abstracted from Filestore::lock() so child classes can implement for
* their own needs.
*
- * @param string $lockName Name of lock to aquire
- * @param string $method Name of method calling us
+ * @param $lockName String: Name of lock to aquire
+ * @param $method String: Name of method calling us
* @return bool
*/
public function lock( $lockName, $method ) {
* @todo fixme - Figure out a way to return a bool
* based on successful lock release.
*
- * @param string $lockName Name of lock to release
- * @param string $method Name of method calling us
+ * @param $lockName String: Name of lock to release
+ * @param $method String: Name of method calling us
*/
public function unlock( $lockName, $method ) {
$lockName = $this->addQuotes( $lockName );
* Get search engine class. All subclasses of this
* need to implement this if they wish to use searching.
*
- * @return string
+ * @return String
*/
public function getSearchEngine() {
return "SearchMySQL";
/**
* Construct a database error
- * @param Database $db The database object which threw the error
- * @param string $error A simple error message to be used for debugging
+ * @param $db Database object which threw the error
+ * @param $error A simple error message to be used for debugging
*/
function __construct( Database &$db, $error ) {
$this->db =& $db;
return $ret;
}
- /**#@+
- * @param mixed $res A SQL result
- */
/**
* Free a result object
*/
/**
* Get the number of fields in a result object
* See documentation for mysql_num_fields()
+ * @param $res SQL result object as returned from Database::query(), etc.
*/
function numFields( $res ) {
if ( $res instanceof ResultWrapper ) {
* Get a field name in a result object
* See documentation for mysql_field_name():
* http://www.php.net/mysql_field_name
+ * @param $res SQL result object as returned from Database::query(), etc.
+ * @param $n Int
*/
function fieldName( $res, $n ) {
if ( $res instanceof ResultWrapper ) {
/**
* Change the position of the cursor in a result object
* See mysql_data_seek()
+ * @param $res SQL result object as returned from Database::query(), etc.
+ * @param $row Database row
*/
function dataSeek( $res, $row ) {
if ( $res instanceof ResultWrapper ) {
*
* @private
*
- * @param array $options an associative array of options to be turned into
+ * @param $options Array: an associative array of options to be turned into
* an SQL query, valid keys are listed in the function.
* @return array
*/
/**
* SELECT wrapper
*
- * @param mixed $table Array or string, table name(s) (prefix auto-added)
- * @param mixed $vars Array or string, field name(s) to be retrieved
- * @param mixed $conds Array or string, condition(s) for WHERE
- * @param string $fname Calling function name (use __METHOD__) for logs/profiling
- * @param array $options Associative array of options (e.g. array('GROUP BY' => 'page_title')),
+ * @param $table Mixed: Array or string, table name(s) (prefix auto-added)
+ * @param $vars Mixed: Array or string, field name(s) to be retrieved
+ * @param $conds Mixed: Array or string, condition(s) for WHERE
+ * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
+ * @param $options Array: Associative array of options (e.g. array('GROUP BY' => 'page_title')),
* see Database::makeSelectOptions code for list of supported stuff
* @return mixed Database result resource (feed to Database::fetchObject or whatever), or false on failure
*/
/**
* UPDATE wrapper, takes a condition array and a SET array
*
- * @param string $table The table to UPDATE
- * @param array $values An array of values to SET
- * @param array $conds An array of conditions (WHERE). Use '*' to update all rows.
- * @param string $fname The Class::Function calling this function
- * (for the log)
- * @param array $options An array of UPDATE options, can be one or
+ * @param $table String: The table to UPDATE
+ * @param $values Array: An array of values to SET
+ * @param $conds Array: An array of conditions (WHERE). Use '*' to update all rows.
+ * @param $fname String: The Class::Function calling this function
+ * (for the log)
+ * @param $options Array: An array of UPDATE options, can be one or
* more of IGNORE, LOW_PRIORITY
* @return bool
*/
* Make UPDATE options for the Database::update function
*
* @private
- * @param array $options The options passed to Database::update
+ * @param $options Array: The options passed to Database::update
* @return string
*/
function makeUpdateOptions( $options ) {
/**
* MSSQL doubles quotes instead of escaping them
- * @param string $s String to be slashed.
+ * @param $s String to be slashed.
* @return string slashed string.
*/
function strencode($s) {
*
* DO NOT put the join condition in $conds
*
- * @param string $delTable The table to delete from.
- * @param string $joinTable The other table.
- * @param string $delVar The variable to join on, in the first table.
- * @param string $joinVar The variable to join on, in the second table.
- * @param array $conds Condition array of field names mapped to variables, ANDed together in the WHERE clause
+ * @param $delTable String: The table to delete from.
+ * @param $joinTable String: The other table.
+ * @param $delVar String: The variable to join on, in the first table.
+ * @param $joinVar String: The variable to join on, in the second table.
+ * @param $conds Array: Condition array of field names mapped to variables, ANDed together in the WHERE clause
+ * @param $fname String: Calling function name
*/
function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = 'Database::deleteJoin' ) {
if ( !$conds ) {
/**
* Returns an SQL expression for a simple conditional.
*
- * @param string $cond SQL expression which will result in a boolean value
- * @param string $trueVal SQL expression to return if true
- * @param string $falseVal SQL expression to return if false
+ * @param $cond String: SQL expression which will result in a boolean value
+ * @param $trueVal String: SQL expression to return if true
+ * @param $falseVal String: SQL expression to return if false
* @return string SQL fragment
*/
function conditional( $cond, $trueVal, $falseVal ) {