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Tech Tip: Using Alter Table to create Auto Increment/Generate in a new Field
PRODUCT: 4D | VERSION: 13.4 | PLATFORM: Mac & Win
Published On: January 3, 2014

The ALTER TABLE command has the ability to create a field in a table to enable the auto increment on an Integer (Integer/Long Integer/Integer 64) and/or auto generate on a UUID through SQL. Enabling the attribute of auto increment/generate in the command can only be done during the time of creating the field only. It would mean that an exsisting field cannot enable the attribute.

Example of creating a field and auto incrementing an Integer:

C_TEXT($textQuery;$tableName;$fieldName;$fieldType)

$tableName:="Table_1"
$fieldName:="Age"
$fieldType:="INT"

$textQuery:="ALTER TABLE "+$tableName+" ADD "+$fieldName+" "+$fieldType+" AUTO_INCREMENT";"

Begin SQL
   EXECUTE IMMEDIATE: $textQuery;
END SQL



Result of the code executed in red:

Example of creating a field and auto generating a UUID:

$tableName:="Table_1"
$fieldName:="ID"
$fieldType:="UUID"

$textQuery:="ALTER TABLE "+$tableName+" ADD "+$fieldName+" "+$fieldType+" AUTO_GENERATE";"

Begin SQL
   EXECUTE IMMEDIATE: $textQuery;
End SQL



Result of the code executed in red:



See Also: