Data types

The data type specifies the range of permitted values for a column. In SQL, the data type for a column is defined with the column definition (see "Column") in the statements CREATE TABLE or ALTER TABLE.

BLOBs (Binary Large Objects) are based on existing data types in SESAM/SQL and are therefore not a new data type in themselves. The structure and method for processing such objects are described in section “BLOB constructs”.

Data type	SQL syntax	Range of values
Alphanumeric data type: fixed-length alphanumeric string	CHAR[ACTER] [(length)] length: fixed column length in characters; unsigned integer, 1 through 256	Alphanumeric string of length length The CHAR data type is stored with its significant length only, without trailing spaces.
Alphanumeric data type: alphanumeric string of length 0 through max	{ CHAR[ACTER] VARYING(max) | VARCHAR (max) } max: maximum length of column in characters; unsigned integer, 1 through 32000	Alphanumeric string shorter than or equal to the length max
National data type: fixed-length national string	{ NATIONAL CHAR[ACTER] | NCHAR } [(cu_length [CODE_UNITS])] cu_length: fixed column length in code units (1 code unit = 2 byte); unsigned integer, 1 through 128	National sring of length cu_length The NCHAR data type is stored with its significant length only, without trailing spaces
National data type: national string of length 0 through cu_max	{ NATIONAL CHAR[ACTER] VARYING | NCHAR VARYING | NVARCHAR } (cu_max [CODE_UNITS]) cu_max: maximum length of column in code units (1 code unit = 2 byte); unsigned integer, 1 through 16000	National stringshorter than or equal to the length cu_max
Numeric: small integer	SMALLINT	-215 through 2<sup>15 </sup>through 215-1
Numeric: large integer	INT[EGER]	-231 through 231-1
Numeric: fixed-point number	NUMERIC [(precision[,scale])] precision: number of decimal digits; unsigned integer, 1 through 31 scale: number of digits after the decimal point; unsigned integer, 0 through precision	Fixed-point numbers with a value of 0 or in the range 10-scale through 10precision-scale-10-scale The NUMERIC and DECIMAL data types are stored with their significant length only, without leading zeros.
Numeric: fixed-point number	DEC[IMAL] [(precision[,scale])] precision: number of decimal digits; unsigned integer, 1 through 31 scale: number of digits after the decimal point; unsigned integer, 0 through precision
Numeric: single-precision floating-point number	REAL	Floating-point numbers with a value of 0 or in the range 5.4E-79 through 7.2E+75
Numeric: double-precision floating-point number	DOUBLE PRECISION
Numeric: floating- point number	FLOAT[(precision)] precision: minimum number of binary digits for the mantissa; unsigned integer, 1 through 53
Time data type: date	DATE	Date specification from the range 0001-01-01 through 9999-12-31
Time data type: time	TIME(3)	Time specification from the range 00:00:00.000 through 23:59:61.999
Time data type: time stamp with date and time	TIMESTAMP(3)	Date specification as for DATE, time as for TIME(3)

Tabelle 30: Data types in SESAM/SQL