QueryScript: SQL scripting language

Introducing QueryScript: a programming language aimed for SQL scripting, seamlessly combining scripting power such as flow control & variables with standard SQL statements or RDBMS-specific commands.

QueryScript is available fro MySQL via common_schema, which adds MySQL-specific usage.

What does QueryScript look like? Here are a few code samples:

Turn a bulk DELETE operation into smaller tasks. Throttle in between.

while (DELETE FROM archive.events WHERE ts < CURDATE() LIMIT 1000)
{
  throttle 2;
}

Convert all InnoDB tables in the ‘sakila’ database to compressed format:

foreach ($table, $schema, $engine: table in sakila)
{
  if ($engine = 'InnoDB')
    ALTER TABLE :$schema.:$table ENGINE=InnoDB ROW_FORMAT=COMPRESSED KEY_BLOCK_SIZE=8;
}

Shard your data across multiple schemata:

foreach($shard: {USA, GBR, JAP, FRA})
{
  CREATE DATABASE db_:$shard;
  CREATE TABLE db_:$shard.city LIKE world.City;
  INSERT INTO db_:$shard.city SELECT * FROM world.City WHERE CountryCode = $shard;
}

This tight integration between script and SQL, with the power of iteration, conditional statements, variables, variable expansion, throttling etc., makes QueryScript a power tool, with capabilities superseding those of stored routines, and allowing for simplified, dynamic code.

QueryScript code is interpreted. It’s just a text, so it can be read from a @user_defined_variable, a table column, text file, what have you. For example:

mysql> set @script := "while (TIME(SYSDATE()) < '17:00:00') SELECT * FROM world.City WHERE id = 1 + FLOOR((RAND()*4079));";
mysql> call run(@script);

For more details, consult the QueryScript site.

If you’re a MySQL user/DBA, better read the common_schema QueryScript documentation, to better understand the specific common_schema implementation and enhanced features.

common_schema, including the QueryScript interpreter, can be downloaded from the common_schema project page.