Deletes the named collating sequence.
You cannot delete a collating sequence if it is used by the
database or by any domain in the database.
1 – Environment
You can use the DROP COLLATING SEQUENCE statement:
o In interactive SQL
o Embedded in host language programs to be precompiled
o As part of a procedure in an SQL module
o In dynamic SQL as a statement to be dynamically executed
2 – Format
(B)0[m[1;4mDROP[m[1m [1;4mCOLLATING[m[1m [1;4mSEQUENCE[m[1m qq> <collation-name> [mqwqqqqqqqqqqqqqq[1mqwq>[m [1m [mmq> [1;4mIF[m[1m [1;4mEXISTS[m[1m qqj[m
3 – Arguments
3.1 – collation-name
Specifies the collation-name argument you used when creating the
collating sequence in the CREATE COLLATING SEQUENCE statement.
3.2 – IF_EXISTS
Prevents SQL command language from displaying error messages if
the referenced object does not exist in the database.
4 – Examples
Example 1: Creating, then deleting, a French collating sequence
The following example creates a collating sequence using the
predefined collating sequence FRENCH. It then uses the SHOW
COLLATING SEQUENCE statement to show the defined collating
sequence.
The example next deletes the collating sequence using the
DROP COLLATING SEQUENCE statement. The SHOW COLLATING SEQUENCE
statement shows that the collating sequence no longer exists.
SQL> ATTACH 'FILENAME personnel';
SQL> CREATE COLLATING SEQUENCE FRENCH FRENCH;
SQL> --
SQL> SHOW COLLATING SEQUENCE
User collating sequences in database with filename personnel
FRENCH
SQL> --
SQL> DROP COLLATING SEQUENCE FRENCH;
SQL> --
SQL> SHOW COLLATING SEQUENCE
User collating sequences in database with filename personnel
No collating sequences found
Example 2: Deleting a collating sequence used to define a domain
or database
The following example shows that you cannot delete a collating
sequence if a domain or database is defined using the collating
sequence:
SQL> CREATE COLLATING SEQUENCE SPANISH SPANISH;
SQL> CREATE DOMAIN LAST_NAME_SPANISH CHAR (14)
cont> COLLATING SEQUENCE IS SPANISH;
SQL> --
SQL> SHOW DOMAIN LAST_NAME_SPANISH
LAST_NAME_SPANISH CHAR(14)
Collating sequence: SPANISH
SQL> --
SQL> SHOW COLLATING SEQUENCE
User collating sequences in database with filename personnel
SPANISH
SQL> --
SQL> -- You cannot delete the collating sequence because the
SQL> -- domain LAST_NAME_SPANISH, defined using SPANISH, still exists:
SQL> --
SQL> DROP COLLATING SEQUENCE SPANISH;
%RDB-E-NO_META_UPDATE, metadata update failed
-RDMS-F-COLUSEDFLD, the collating sequence named SPANISH is used in
field LAST_NAME_SPANISH
SQL> --
SQL> -- Delete the domain:
SQL> --
SQL> DROP DOMAIN LAST_NAME_SPANISH;
SQL> --
SQL> -- Now you can delete the collating sequence:
SQL> --
SQL> DROP COLLATING SEQUENCE SPANISH;
SQL> --
SQL> SHOW COLLATING SEQUENCE
User collating sequences in database with filename personnel
No collating sequences found