ALTER COMMAND SYNTXES AND EXAMPLES

ALTER COMMAND syntaxes:----------------------
ADDING COLUMN:
SYNTAX: ALTER TABLE <TABLENAME> ADD <COLUMNNAME> <DATATYPE>
 EG: ALTER TABLE PARTY ADD JDATE DATE

DROPING COLUMN:
SYNTAX: ALTER TABLE <TABLENAME> DROP <COLUMNNAME>
 EG: ALTER TABLE PARTY DROP JDATE

INCREASING DATATYPE LENGH:
SYNTAX:ALTER TABLE <TABLENAME> ADD COLUMNNAME DATATYPE<NEWLENGTH>
EG: ALTER TABLE PARTY ADD PARTYNAME VARCHAR(50)

ADDING CONSTRAINT:
SYNTAX: ALTER TABLE <TABLENAME> ADD CONSTRAINT <CONSTRAINTAME> PRIMARY/UNIQUE/CHECK
/REFERENCES(COLUMNS OR EXPRESSION)
 EG:ALTER TABLE PARTY ADD CONSTRAINT CHK_SAL CHECK (PARTYSAL>100000)
Note: to add primary key or unique the column should have not null defined on it.
      EG:   ALTER TABLE PARTY ADD CONSTRAINT uk  UNIQUE(PARTYNAME)

MODIFYING CONSTRAINT:
SYNTAX: ALTER TABLE <TABLENAME> MODIFY CONSTRAINT <CONSTRAINTAME> PRIMARY/UNIQUE
/CHECK/REFERENCES
 EG:ALTER TABLE PARTY MODIFY CONSTRAINT CHK_SAL
 CHECK (PARTYSAL>100000 AND PARTYSAL<200000)

 DROPING CONSTRAINT:
 SYNTAX:ALTER TABLE <TABLENAME> DROP CONSTRAINT <CONSTRAINTNAME>
 EG: ALTER TABLE PARTY DROP CONSTRAINT CHK_SAL

NO FALLBACK TO FALLBACK:
 SYNTAX: ALTER TABLE <TABLENAME>,FALLBACK
 EG: ALTER TABLE PARTY,FALLBACK

 CHANGING DATA BLOCKSIZE:
 SYNTAX:ALTER TABLE <TABLENAME>, DATABLOCKSIZE=<MEMORY>BYTES IMMEDIATE
 EG: ALTER TABLE <TABLENAME>, DATABLOCKSIZE=1200 BYTES IMMEDIATE

 RENAMING THE COLUMN:
 SYNTAX: ALTER TABLE <TABLENAME> RENAME <OLDNAME>TO <NEWNAME>
  EG: ALTER TABLE PARTY RENAME PARTYCD TO PARTYCODE

RENAMING A TABLE:
SYN:  RENAME TABLE <OLDTABLE> TO <NEW TABLE>
EG: RENAME TABLE PARTY TO PARTY_NEW

ADDING COMPRESS:
ALTER TABLE PARTY ADD PARTYCODE COMPRESS NULL;
ALTER TABLE PARTY ADD ACCOUNTTYPE COMPRESS 'sAVINGS';
ALTER TABLE PARTY ADD ACCOUNTTYPE COMPRESS 'sAVINGS','Current';