SQL compatibility table

Compatible Compatible with warning Not compatible Unknown

Example of data type	MySQL MariaDB	Oracle Database	PostgreSQL	Microsoft SQL Server	IBM DB2	SQLite	Other database systems		ANSI/ISO standard	Universal alternative
INT	Yes	NUMBER(38)	Yes	Yes	Yes	INT or TEXT	Access Firebird Interbase	Informix CUBRID Sybase	SQL-92	INTEGER
INTEGER	Yes	NUMBER(38)	Yes	Yes	Yes	INT or TEXT	Microsoft Access		SQL-92	INT
SMALLINT	Yes	NUMBER(38)	Yes	Yes	Yes	INT or TEXT	Access Informix CUBRID	Firebird & Sybase	SQL-92
DECIMAL(9,2)	max 65 digits	NUMBER(9,2)	1000 digits or more	max 38 digits	Yes	REAL or TEXT	Informix	Microsoft Access	SQL-92	NUMERIC(9,2)
NUMERIC(9,2)	max 65 digits	NUMBER(9,2)	1000 digits or more	max 38 digits	Yes	REAL or TEXT	Microsoft Access		SQL-92	DECIMAL(9,2)
DOUBLE PRECISION	double-precision (8 bytes)	FLOAT(126)	15 digits (8 bytes)	FLOAT(53)	double-precision	REAL or TEXT	Microsoft Access	Informix	SQL-92	FLOAT(53)
FLOAT(24)	max 53	max 126	max 53	max 53	max 53	REAL or TEXT			SQL-92
CHAR(255)	max 255	max 2000	max 10485760	Yes	max 255 254 before v10	unlimited TEXT	Firebird Sybase Informix	CUBRID: max 32767	SQL-92
VARCHAR(126)	max 65535	max 4000 or 32767	max 10485760	max 8000	max 32672	unlimited TEXT	Informix: max 255	Microsoft Access	SQL-92
Column properties
NOT NULL	Yes	Yes	Yes	Yes	Yes	Yes
PRIMARY KEY	Yes	Yes	Yes	Yes	Yes	Yes
DEFAULT value	Yes	Yes	Yes	Yes	Yes	Yes			SQL-92
UNIQUE	Yes	Yes	Yes	Yes	Yes	Yes
Other column properties
AUTO_INCREMENT	Yes	No	?	No	No	No	Sybase			INSERT ... SELECT COALESCE(MAX(id)+1,1)...
IDENTITY(1,1)	No	No	?	Yes	?	No	Sybase			INSERT ... SELECT COALESCE(MAX(id)+1,1)...
GENERATED BY DEFAULT AS IDENTITY	?	since 12c (2013)	?	?	Yes	No				INSERT ... SELECT COALESCE(MAX(id)+1,1)...
UNSIGNED	integer	No	No	No	No	signed INT	Access Firebird CUBRID	Sybase		INSERT INTO tab (col) VALUES (int-2147483647) SELECT col+2147483647 FROM tab
Date/time types
DATE	Yes	date + time	Yes	Yes	Yes	TEXT or INT			SQL-92	INT (yyyymmdd)
DATETIME	Yes	No	No	Yes	No	TEXT or INT				INT (unix timestamp)
TIME	Yes	No	Yes	Yes	Yes	TEXT or INT			SQL-92	INT (hhmmss)
TIMESTAMP	Yes	Yes	Yes	No	Yes	TEXT or INT			SQL-92	INT (unix timestamp)
Binary data
BLOB	max 65535	Yes	No	No	max 2GB	Yes	Sybase	Microsoft Access		VARCHAR(4000) insert to_base64(val); select from_base64(col)
BYTEA	No	No	Up to 1GB	No	No	BLOB	Microsoft Access			VARCHAR(4000) insert to_base64(val); select from_base64(col)
BINARY(32)	max 255	No	No	max 8000	max 255	BLOB	Sybase: max 32767	Microsoft Access	SQL:2008	CHAR(64) insert hex(val); select unhex(col)
VARBINARY(3000)	max 65535	No	No	max 8000	max 32704	BLOB	Sybase: max 32767	Microsoft Access		VARCHAR(4000) insert to_base64(val); select from_base64(col)
Other binary data
CLOB	No	Yes	No	No	max 2GB	BLOB				VARCHAR(4000)
IMAGE	?	?	?	Deprecated	?	BLOB				VARCHAR(4000) insert to_base64(val); select from_base64(col)
Boolean types
BOOLEAN	TINYINT	No	Yes	BIT	Yes	INT			SQL:1999	CHAR(1)
BIT(8)	max 64	?	Yes	boolean value	?	TEXT	CUBRID		~~SQL:1999~~	CHAR(8)
BIT VARYING(8)	No	?	Yes	No	?	TEXT			~~SQL:1999~~	VARCHAR(8)
Other character types
NCHAR(255)	No	?	?	Yes	?	unlimited TEXT				CHAR(255)
NTEXT	No	?	?	Deprecated	?	TEXT				VARCHAR(4000)
NVARCHAR(126)	No	?	?	Yes	?	unlimited TEXT	Informix: max 255			VARCHAR(126)
LVARCHAR(126)	?	?	?	?	?	unlimited TEXT	Informix: max 32739			VARCHAR(126)
TEXT	Yes	No	Yes	?	?	Yes				VARCHAR(4000)
NATIONAL CHARACTER(255)	No	?	?	Yes	?	unlimited TEXT			SQL-92	CHAR(255)
NATIONAL CHARACTER VARYING(126)	No	?	?	Yes	?	unlimited TEXT			SQL-92	VARCHAR(126)
Other decimal types
FLOAT	single-precision (4 bytes)	FLOAT(126)	DOUBLE PRECISION	FLOAT(53)	double-precision	REAL or TEXT	Microsoft Access		SQL-92	FLOAT(53)
REAL	DOUBLE PRECISION	FLOAT(63)	6 digits (4 bytes)	FLOAT(24)	single-precision	REAL or TEXT	Microsoft Access	Informix	SQL-92	FLOAT(24)
DEC(9,2)	Yes	No	No	Yes	Yes	REAL or TEXT				DECIMAL(9,2)
DOUBLE	Yes	No	No	No	Yes	REAL or TEXT	Informix	Microsoft Access		DOUBLE PRECISION
Other integer types
BIGINT	Yes	NUMBER(19)	Yes	Yes	Yes	INT or TEXT	Firebird & Interbase	Sybase Informix CUBRID	SQL:2003	DECIMAL(19,0)
MEDIUMINT	Yes	No	No	No	No	INT or TEXT	Microsoft Access & Firebird	Sybase & CUBRID		INT
TINYINT	Yes	No	No	unsigned	No	INT or TEXT	Sybase (signed)	Firebird & CUBRID	SQL-92	SMALLINT
SERIAL	?	No	Yes	?	?	INT or TEXT	Informix

Notes

SQLite accepts anything as column type because each value are dynamically typed
Date literals can have different format across database systems
PostgreSQL needs only 1 byte of overhead to store short string up to VARCHAR(126)
MySQL and MariaDB need only 1 byte of overhead to store string up to VARCHAR(255)
DECIMAL or NUMERIC type with precision greater than 9 require more storage
Always use single quote for string literal (never use double quotes)

Reference manuals

SQL standard publications