SQL Keywords Compléter Référence
Reserved et non-reserved SQL keywords across le SQL standard et major dialects.
Reserved Keywords
Reserved keywords have special meaning in SQL and cannot be used as identifiers without quoting. The core reserved words include SELECT, FROM, WHERE, INSERT, UPDATE, DELETE, and CREATE. Each dialect reserves additional words, so a name that is valid in one database may require quoting in another. Using non-reserved alternatives or quoting consistently improves portability across database engines.
- SELECT
- Query data from tables
- INSERT
- Add rows to a table
- UPDATE
- Modify existing rows
- DELETE
- Remove rows
- CREATE
- Define a new schema object
SELECT * FROM tINSERT INTO t ...UPDATE t SET ...DELETE FROM t ...CREATE TABLE ...Non-Reserved Keywords
Non-reserved keywords have a defined meaning in the grammar but may be used as identifiers. Examples include LEFT, RIGHT, OUTER, and JOIN in some dialects. The distinction between reserved and non-reserved varies by dialect, which is a common source of portability bugs. Checking the specific dialect's keyword list before choosing identifier names prevents future migration issues.
Quoting Identifiers
When an identifier collides with a reserved word, it must be quoted with double quotes in standard SQL, backticks in MySQL, or square brackets in SQL Server. Quoted identifiers are also case-sensitive in standard SQL, unlike unquoted ones which are folded to lowercase or uppercase depending on the dialect. Consistent quoting of all identifiers avoids ambiguity but reduces readability, so it is usually reserved for problematic names.