SQL dialects

The TSqlDialect value controls the format of date, time, datetime, and boolean literals in SQLExpression and SQLValues[]. String and numeric literals are not affected by the dialect. The default dialect is sqlElevateDB. Set it once per application with SetSQLDialect, or supply it per call via the full overload of ParseInput.

Dialect identifiers

Identifier	Target database
`sqlMySQL`	MySQL 5.x+ / MariaDB 10.x+
`sqlElevateDB`	ElevateDB 2.x+
`sqlDBISAM`	DBISAM 4.x
`sqlPostgreSQL`	PostgreSQL 9.x+
`sqlMSSQLServer`	Microsoft SQL Server 2008+
`sqlSQLite`	SQLite 3.x+
`sqlFirebird`	Firebird 3+ / InterBase
`sqlOracle`	Oracle 11g+
`sqlAccess`	Microsoft Access (Jet / ACE)
`sqlBDEParadox`	BDE / Paradox

Date literals (itDate)

Dialect	Format	Example
`sqlMySQL`	`DATE 'yyyy-mm-dd'`	`DATE '2026-03-25'`
`sqlElevateDB`	`DATE 'yyyy-mm-dd'`	`DATE '2026-03-25'`
`sqlDBISAM`	`'yyyy-mm-dd'`	`'2026-03-25'`
`sqlPostgreSQL`	`DATE 'yyyy-mm-dd'`	`DATE '2026-03-25'`
`sqlMSSQLServer`	`'yyyy-mm-dd'`	`'2026-03-25'`
`sqlSQLite`	`'yyyy-mm-dd'`	`'2026-03-25'`
`sqlFirebird`	`DATE 'yyyy-mm-dd'`	`DATE '2026-03-25'`
`sqlOracle`	`TO_DATE('yyyy-mm-dd','YYYY-MM-DD')`	`TO_DATE('2026-03-25','YYYY-MM-DD')`
`sqlAccess`	`#yyyy-mm-dd#`	`#2026-03-25#`
`sqlBDEParadox`	`"dd.mm.yyyy"`	`"25.03.2026"`

Time literals (itTime)

The [.fff] suffix is included only when milliseconds are non-zero. Zero milliseconds always produce a plain hh:mm:ss literal.

Dialect	Format (no ms)	Format (with ms)	Notes
`sqlMySQL`	`TIME 'hh:mm:ss'`	`TIME 'hh:mm:ss.fff'`	3-digit ms
`sqlElevateDB`	`TIME 'hh:mm:ss'`	`TIME 'hh:mm:ss.fff'`	3-digit ms
`sqlDBISAM`	`'hh:mm:ss'`	`'hh:mm:ss.fff'`	3-digit ms
`sqlPostgreSQL`	`TIME 'hh:mm:ss'`	`TIME 'hh:mm:ss.fff'`	3-digit ms
`sqlMSSQLServer`	`'hh:mm:ss'`	`'hh:mm:ss.fff'`	3-digit ms
`sqlSQLite`	`'hh:mm:ss'`	`'hh:mm:ss.fff'`	3-digit ms
`sqlFirebird`	`TIME 'hh:mm:ss'`	`TIME 'hh:mm:ss.ffff'`	4-digit ten-thousandths (ms × 10)
`sqlOracle`	`TO_TIMESTAMP('hh:mm:ss','HH24:MI:SS')`	`TO_TIMESTAMP('hh:mm:ss.fff','HH24:MI:SS.FF3')`	3-digit ms
`sqlAccess`	`#hh:mm:ss#`	`#hh:mm:ss#`	ms dropped
`sqlBDEParadox`	`"hh:mm:ss"`	`"hh:mm:ss"`	ms dropped

Firebird note: Firebird stores sub-second time as ten-thousandths of a second (0–9999). The parser multiplies the parsed milliseconds by 10 to produce the 4-digit value. For example, 500 ms is stored as 5000 ten-thousandths and the literal is TIME '09:30:15.5000'.

DateTime / TIMESTAMP literals (itDateTime)

The [.fff] / [.ffff] suffix follows the same rules as for time literals above.

Dialect	Format (no ms)	Format (with ms)	Notes
`sqlMySQL`	`'yyyy-mm-dd hh:mm:ss'`	`'yyyy-mm-dd hh:mm:ss.fff'`	3-digit ms
`sqlElevateDB`	`TIMESTAMP 'yyyy-mm-dd hh:mm:ss'`	`TIMESTAMP 'yyyy-mm-dd hh:mm:ss.fff'`	3-digit ms
`sqlDBISAM`	`'yyyy-mm-dd hh:mm:ss'`	`'yyyy-mm-dd hh:mm:ss.fff'`	3-digit ms
`sqlPostgreSQL`	`TIMESTAMP 'yyyy-mm-dd hh:mm:ss'`	`TIMESTAMP 'yyyy-mm-dd hh:mm:ss.fff'`	3-digit ms
`sqlMSSQLServer`	`'yyyy-mm-dd hh:mm:ss'`	`'yyyy-mm-dd hh:mm:ss.fff'`	3-digit ms
`sqlSQLite`	`'yyyy-mm-dd hh:mm:ss'`	`'yyyy-mm-dd hh:mm:ss.fff'`	3-digit ms
`sqlFirebird`	`TIMESTAMP 'yyyy-mm-dd hh:mm:ss'`	`TIMESTAMP 'yyyy-mm-dd hh:mm:ss.ffff'`	4-digit ten-thousandths (ms × 10)
`sqlOracle`	`TO_TIMESTAMP('yyyy-mm-dd hh:mm:ss','YYYY-MM-DD HH24:MI:SS')`	`TO_TIMESTAMP('yyyy-mm-dd hh:mm:ss.fff','YYYY-MM-DD HH24:MI:SS.FF3')`	3-digit ms
`sqlAccess`	`#yyyy-mm-dd hh:mm:ss#`	`#yyyy-mm-dd hh:mm:ss#`	ms dropped
`sqlBDEParadox`	`"dd.mm.yyyy hh:mm:ss"`	`"dd.mm.yyyy hh:mm:ss"`	ms dropped

Boolean literals (itBoolean)

Dialect	True	False
`sqlMySQL`	`TRUE`	`FALSE`
`sqlElevateDB`	`TRUE`	`FALSE`
`sqlDBISAM`	`TRUE`	`FALSE`
`sqlPostgreSQL`	`TRUE`	`FALSE`
`sqlMSSQLServer`	`1`	`0`
`sqlSQLite`	`1`	`0`
`sqlFirebird`	`TRUE`	`FALSE`
`sqlOracle`	`1`	`0`
`sqlAccess`	`True`	`False`
`sqlBDEParadox`	`TRUE`	`FALSE`

String literals

String literals are dialect-independent. Every itString token is wrapped in single quotes using Delphi’s QuotedStr convention: internal single quotes are doubled.

O'Brien   →   'O''Brien'

Numeric literals

Integer, decimal, and float literals are dialect-independent. The decimal separator is always . regardless of the runtime locale.

itDecimal: 1,99  →  1.9900
itFloat:   1,5   →  1.5

LIKE patterns

The ESCAPE '\' clause appended to LIKE expressions is dialect-independent, with one exception: sqlBDEParadox does not receive an ESCAPE clause because BDE SQL layer support for it is unreliable. See Operators for details.