Function apply_paging 

pub fn apply_paging(
    sql: &str,
    limit: Option<usize>,
    offset: Option<usize>,
    backend: Backend,
) -> Result<String, SqlError>

Apply dialect-specific LIMIT / OFFSET paging to a SQL statement.

Returns the original SQL unchanged if:

• both limit and offset are None
• the SQL already contains a LIMIT or OFFSET or FETCH clause
• the SQL contains multiple statements (;)

Dialects

Backend	Syntax
Postgres, SQLite, MySQL	LIMIT {n} OFFSET {m}
MSSQL	OFFSET {m} ROWS FETCH NEXT {n} ROWS ONLY
Oracle (12c+)	OFFSET {m} ROWS FETCH NEXT {n} ROWS ONLY

For MSSQL and Oracle, if no ORDER BY is present, a synthetic ORDER BY (SELECT NULL) / ORDER BY 1 is injected and a warning can be emitted by the caller.