CONVERT function [Data type conversion]

Function

Returns an expression converted to a supplied data type.

Syntax

CONVERT ( data-type, expression [, format-style ] )

Parameters

data-type The data type to which the expression is converted

expression The expression to be converted

format-style For converting strings to date or time data types and vice versa, format-style is a style code number that describes the date format string to be used. Table 5-13 lists the meanings of the values of the format-style argument.

**Table 5-13: CONVERT format style code output**
Without century (yy)	With century (yyyy)	Output
-	0 or 100	mmm dd yyyy hh:nnAM (or PM)
1	101	mm/dd/yy[yy]
2	102	[yy]yy.mm.dd
3	103	dd/mm/yy[yy]
4	104	dd.mm.yy[yy]
5	105	dd-mm-yy[yy]
6	106	dd mmm yy[yy]
7	107	mmm dd, yy[yy]
8	108	hh:nn:ss
-	9 or 109	mmm dd yyyy hh:nn:ss:sssAM (or PM)
10	110	mm-dd-yy[yy]
11	111	[yy]yy/mm/dd
12	112	[yy]yymmdd
13	113	dd mmm yyyy hh:nn:ss:sss (24 hour clock, Europe default + milliseconds, 4-digit year)
14	114	hh:nn:ss (24 hour clock)
20	120	yyyy-mm-dd hh:nn:ss (24-hour clock, ODBC canonical, 4-digit year)
21	121	yyyy-mm-dd hh:nn:ss.sss (24 hour clock, ODBC canonical with milliseconds, 4-digit year)
-	365	yyyyjjj (as a string or integer, where jjj is the Julian day number from 1 to 366 within the year)

If no format-style argument is provided, style code 0 is used.

Examples

The following statements illustrate the use of format styles:

SELECT CONVERT( CHAR( 20 ), order_date, 104 )
FROM sales_order

order_date
16.03.1993
20.03.1993
23.03.1993
25.03.1993
...

SELECT CONVERT( CHAR( 20 ), order_date, 7 )
FROM sales_order

order_date
mar 16, 93
mar 20, 93
mar 23, 93
mar 25, 93
...

The following statements illustrate the use of the format style 365, which converts data of type DATE and DATETIME to and from either string or integer type data:

CREATE TABLE tab
   (date_col DATE, int_col INT, char7_col CHAR(7));
INSERT INTO tab (date_col, int_col, char7_col)
   VALUES (‘Dec 17, 2004’, 2004352, ‘2004352’);

SELECT CONVERT(VARCHAR(8), tab.date_col, 365) FROM tab; returns ‘2004352’

SELECT CONVERT(INT, tab.date_col, 365) from tab; returns 2004352

SELECT CONVERT(DATE, tab.int_col, 365) FROM TAB; returns 2004-12-17

SELECT CONVERT(DATE, tab.char7_col, 365) FROM tab; returns 2004-12-17

The following statement illustrates conversion to an integer, and returns the value 5.

SELECT CONVERT( integer, 5.2 ) FROM iq_dummy

Standards and compatibility

SQL92 Vendor extension.

Sybase Compatible with Adaptive Server Enterprise and Adaptive Server Anywhere, except for format style 365, which is an IQ only extension.