--disable_warnings DROP TABLE IF EXISTS t1,t2,t3,t4; --enable_warnings # Create tables CREATE TABLE t1(c1 YEAR NOT NULL,c2 YEAR, PRIMARY KEY(c1)); CREATE TABLE t2(c1 YEAR NOT NULL, c2 YEAR, UNIQUE INDEX idx(c1,c2)); CREATE TABLE t3(c1 YEAR(2) NOT NULL,c2 YEAR(2), PRIMARY KEY(c1)); CREATE TABLE t4(c1 YEAR(2), c2 YEAR(2), UNIQUE INDEX idx(c1,c2)); #Insert as 4-digit number format in the range '1901' to '2155' INSERT INTO t1 VALUES (1901,1901),(1970,1970),(1999,1999),(2000,2000),(2155,2155); INSERT INTO t2 VALUES (1901,1901),(1970,1970),(1999,1999),(2000,2000),(2155,2155); INSERT INTO t3 VALUES (1901,1901),(1970,1970),(1999,1999),(2000,2000),(2155,2155); INSERT INTO t4 VALUES (1901,1901),(1970,1970),(1999,1999),(2000,2000),(2155,2155); #Insert as 4-digit string format in the range '1901' to '2155' INSERT INTO t1 VALUES ('1902','1902'),('1971','1971'),('1998','1998'),('2001','2001'),('2154','2154'); INSERT INTO t2 VALUES ('1902','1902'),('1971','1971'),('1998','1998'),('2001','2001'),('2154','2154'); INSERT INTO t3 VALUES ('1902','1902'),('1971','1971'),('1998','1998'),('2001','2001'),('2154','2154'); INSERT INTO t4 VALUES ('1902','1902'),('1971','1971'),('1998','1998'),('2001','2001'),('2154','2154'); #Insert as 2-digit number format INSERT INTO t1 VALUES (04,04),(64,64),(69,69),(97,97); INSERT INTO t2 VALUES (04,04),(64,64),(69,69),(97,97); INSERT INTO t3 VALUES (04,04),(64,64),(69,69),(97,97); INSERT INTO t4 VALUES (04,04),(64,64),(69,69),(97,97); #Insert as 2-digit string format INSERT INTO t1 VALUES ('05','05'),('65','65'),('75','75'),('95','95'); INSERT INTO t2 VALUES ('05','05'),('65','65'),('75','75'),('95','95'); INSERT INTO t3 VALUES ('05','05'),('65','65'),('75','75'),('95','95'); INSERT INTO t4 VALUES ('05','05'),('65','65'),('75','75'),('95','95'); #Insert permissible NULLs INSERT INTO t1 VALUES ('09',null),('61',null),('79',null),('96',null); INSERT INTO t2 VALUES ('09',null),('61',null),('79',null),('96',null); INSERT INTO t3 VALUES ('09',null),('61',null),('79',null),('96',null); INSERT INTO t4 VALUES ('09',null),('61',null),('79',null),('96',null); --sorted_result SELECT * FROM t1; --sorted_result SELECT * FROM t2; --sorted_result SELECT * FROM t3; --sorted_result SELECT * FROM t4; #Deleting the specified rows --sorted_result SELECT c1 FROM t1 WHERE c1='2005'; DELETE FROM t1 WHERE c1='2005'; --sorted_result SELECT c1 FROM t1; # Delete rows with null attributes --sorted_result SELECT c2 FROM t2 WHERE c2=null; DELETE FROM t2 WHERE c2=null LIMIT 2; --sorted_result SELECT c2 FROM t2; #Delete order by limit --sorted_result SELECT c1 FROM t4 WHERE c1 < '55'; DELETE FROM t4 WHERE c1 < '65' ORDER BY c1 LIMIT 5; --sorted_result SELECT c1 FROM t4; #Delete by range values DELETE FROM t2 WHERE c1=2009 AND c2=null; --sorted_result SELECT c2 FROM t2; DELETE FROM t1 WHERE c1=1979 OR c1=2154; --sorted_result SELECT c2 FROM t1; DELETE FROM t4 WHERE c2 IN (01,54,65,69,null) LIMIT 2; --sorted_result SELECT c1 FROM t4; #Multi table delete DELETE t3,t4 FROM t3,t4 WHERE t3.c1=61 AND t4.c2=4; # Delete using various access methods # Delete using Const # EXPLAIN SELECT * FROM t1 WHERE c1=2064 AND c2=2064; DELETE FROM t1 WHERE c1=2064 AND c2=2064; --sorted_result SELECT * FROM t1; # Delete using range # EXPLAIN SELECT * FROM t1 WHERE c1 BETWEEN 2000 AND 2010; DELETE FROM t1 WHERE c1 BETWEEN 2000 AND 2010 LIMIT 2; --sorted_result SELECT * FROM t1; # EXPLAIN SELECT * FROM t1 WHERE c1 IN (2155,2009,1975); DELETE FROM t1 WHERE c1 IN (2155,2009,1975) LIMIT 2; --sorted_result SELECT * FROM t1; # Delete using eq_ref # EXPLAIN SELECT * FROM t1,t2 WHERE t1.c1=t2.c1 AND t1.c2=t2.c2; DELETE t1,t2 FROM t1,t2 WHERE t1.c1=t2.c1 AND t1.c2=t2.c2; --sorted_result SELECT * FROM t1; --sorted_result SELECT * FROM t2; --sorted_result SELECT * FROM t3; --sorted_result SELECT * FROM t4; #Drop tables DROP TABLE IF EXISTS t1,t2,t3,t4;