Table 7 1   Differences in DB2 and MySQL grouping, having and ordering

MySQL

DB2 UDB

Example

 BIT_AND

Not available. Example 

MySQL:

provided

select bit_and(a),a from t1 

group by a

DB2 UDB:

Refer to UDF example 

BITAND in Appendix A.1, 

 Sample code for 

BIT_AND  on page 336

 BIT_OR

Not available

MySQL:

select bit_or(a),a from t1 

group by a

DB 2UDB:

Compare to UDF BitAnd in 

Appendix A.1,  Sample 

code for BIT_AND  on 

page 336

COUNT(DISTINCT 

DB2 allows only one 

MySQL:

expr,expr,...)

expression: 

select count(distinct a,b),a 

COUNT(DISTINCT expr).

from t1 group by a 

Use CONCAT for 

character data type or 

DB2 UDB:

CHAR and CONCAT on 

select count(distinct 

numeric data types

concat(a,b)), a from t1 

group by a

 STD

STDDEV

MySQL:

select std(a),a from t1 

group by a

DB2 UDB:

select stddev(a), a from t1 

group by a

 STDDEV

STDDEV

MySQL:

select stddev(a),a from t1 

group by a

DB2 UDB:

select stddev(a),a from t1 

group by a

160 

MySQL to DB2 UDB Conversion Guide