# SQL

The SQL language support in eKuiper includes Data Definition Language (DDL), Data Manipulation Language (DML) and Query Language. The SQL support in eKuiper is a subset of ANSI SQL and has some customized extensions.

# SQL in source definition

When create and manage stream or table source, SQL DDL and DML are used as the command payload. Check streams and tables for detail.

# SQL queries in rules

In rules, SQL queries are used to define the business logic. Please check sql reference for detail.