Macro Rules

These rules change the final SQL sent to the database, such as argument-driven sorting or computing sharded table names.

Rule	Description
`@{macro, name}`	MACRO runs the SQL macro named `name`; macros can contain predefined SQL.
`@{ifmacro, testExpr, name}`	IFMACRO is MACRO with a guard; when `testExpr` is true, the macro is executed.
`@{iftext, testExpr, content}`	IFTEXT inserts `content` verbatim into SQL when `testExpr` is true.

MACRO / IFMACRO

MACRO inlines predefined SQL macros into the final SQL. Referencing a missing macro raises an error at execution.

1. Register a SQL macro
DynamicContext registry = jdbcTemplate.getRegistry();
registry.addMacro("includeSeq", "and seq = :seq");

2. Use macro in query
select * from users where
    status = :status
    @{macro, includeSeq}

3. Final executed SQL
select * from users where status = :status and seq = :seq

IFMACRO adds a guard expression.

Use IFMACRO
select * from users where
    status = :status
    @{ifmacro, status > 2, includeSeq}

IFTEXT inserts content verbatim when testExpr is true.

1. Usage
select * from users where
    status = :status
    @{iftext, status > 2, and age = 36 }

2. When status > 2
select * from users where status = :status and age = 36

3. When status <= 2
select * from users where status = :status

info

content is inserted as raw text. If it contains arguments, consider other rules.