📄 alter_table.result
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drop table if exists t1,t2;drop database if exists mysqltest;create table t1 (col1 int not null auto_increment primary key,col2 varchar(30) not null,col3 varchar (20) not null,col4 varchar(4) not null,col5 enum('PENDING', 'ACTIVE', 'DISABLED') not null,col6 int not null, to_be_deleted int);insert into t1 values (2,4,3,5,"PENDING",1,7);alter table t1add column col4_5 varchar(20) not null after col4,add column col7 varchar(30) not null after col5,add column col8 datetime not null, drop column to_be_deleted,change column col2 fourth varchar(30) not null after col3,modify column col6 int not null first;select * from t1;col6 col1 col3 fourth col4 col4_5 col5 col7 col81 2 3 4 5 PENDING 0000-00-00 00:00:00drop table t1;create table t1 (bandID MEDIUMINT UNSIGNED NOT NULL PRIMARY KEY, payoutID SMALLINT UNSIGNED NOT NULL);insert into t1 (bandID,payoutID) VALUES (1,6),(2,6),(3,4),(4,9),(5,10),(6,1),(7,12),(8,12);alter table t1 add column new_col int, order by payoutid,bandid;select * from t1;bandID payoutID new_col6 1 NULL3 4 NULL1 6 NULL2 6 NULL4 9 NULL5 10 NULL7 12 NULL8 12 NULLalter table t1 order by bandid,payoutid;select * from t1;bandID payoutID new_col1 6 NULL2 6 NULL3 4 NULL4 9 NULL5 10 NULL6 1 NULL7 12 NULL8 12 NULLdrop table t1;CREATE TABLE t1 (GROUP_ID int(10) unsigned DEFAULT '0' NOT NULL,LANG_ID smallint(5) unsigned DEFAULT '0' NOT NULL,NAME varchar(80) DEFAULT '' NOT NULL,PRIMARY KEY (GROUP_ID,LANG_ID),KEY NAME (NAME));ALTER TABLE t1 CHANGE NAME NAME CHAR(80) not null;SHOW FULL COLUMNS FROM t1;Field Type Collation Null Key Default Extra Privileges CommentGROUP_ID int(10) unsigned NULL NO PRI 0 # LANG_ID smallint(5) unsigned NULL NO PRI 0 # NAME char(80) latin1_swedish_ci NO MUL # DROP TABLE t1;create table t1 (n int);insert into t1 values(9),(3),(12),(10);alter table t1 order by n;select * from t1;n391012drop table t1;CREATE TABLE t1 (id int(11) unsigned NOT NULL default '0',category_id tinyint(4) unsigned NOT NULL default '0',type_id tinyint(4) unsigned NOT NULL default '0',body text NOT NULL,user_id int(11) unsigned NOT NULL default '0',status enum('new','old') NOT NULL default 'new',PRIMARY KEY (id)) ENGINE=MyISAM;ALTER TABLE t1 ORDER BY t1.id, t1.status, t1.type_id, t1.user_id, t1.body;DROP TABLE t1;CREATE TABLE t1 (AnamneseId int(10) unsigned NOT NULL auto_increment,B BLOB,PRIMARY KEY (AnamneseId)) engine=myisam;insert into t1 values (null,"hello");LOCK TABLES t1 WRITE;ALTER TABLE t1 ADD Column new_col int not null;UNLOCK TABLES;OPTIMIZE TABLE t1;Table Op Msg_type Msg_texttest.t1 optimize status OKDROP TABLE t1;create table t1 (i int unsigned not null auto_increment primary key);insert into t1 values (null),(null),(null),(null);alter table t1 drop i,add i int unsigned not null auto_increment, drop primary key, add primary key (i);select * from t1;i1234drop table t1;create table t1 (name char(15));insert into t1 (name) values ("current");create database mysqltest;create table mysqltest.t1 (name char(15));insert into mysqltest.t1 (name) values ("mysqltest");select * from t1;namecurrentselect * from mysqltest.t1;namemysqltestalter table t1 rename mysqltest.t1;ERROR 42S01: Table 't1' already existsselect * from t1;namecurrentselect * from mysqltest.t1;namemysqltestdrop table t1;drop database mysqltest;create table t1 (n1 int not null, n2 int, n3 int, n4 float,unique(n1),key (n1, n2, n3, n4),key (n2, n3, n4, n1),key (n3, n4, n1, n2),key (n4, n1, n2, n3) );alter table t1 disable keys;show keys from t1;Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Commentt1 0 n1 1 n1 A 0 NULL NULL BTREE t1 1 n1_2 1 n1 A NULL NULL NULL BTREE disabledt1 1 n1_2 2 n2 A NULL NULL NULL YES BTREE disabledt1 1 n1_2 3 n3 A NULL NULL NULL YES BTREE disabledt1 1 n1_2 4 n4 A NULL NULL NULL YES BTREE disabledt1 1 n2 1 n2 A NULL NULL NULL YES BTREE disabledt1 1 n2 2 n3 A NULL NULL NULL YES BTREE disabledt1 1 n2 3 n4 A NULL NULL NULL YES BTREE disabledt1 1 n2 4 n1 A NULL NULL NULL BTREE disabledt1 1 n3 1 n3 A NULL NULL NULL YES BTREE disabledt1 1 n3 2 n4 A NULL NULL NULL YES BTREE disabledt1 1 n3 3 n1 A NULL NULL NULL BTREE disabledt1 1 n3 4 n2 A NULL NULL NULL YES BTREE disabledt1 1 n4 1 n4 A NULL NULL NULL YES BTREE disabledt1 1 n4 2 n1 A NULL NULL NULL BTREE disabledt1 1 n4 3 n2 A NULL NULL NULL YES BTREE disabledt1 1 n4 4 n3 A NULL NULL NULL YES BTREE disabledinsert into t1 values(10,RAND()*1000,RAND()*1000,RAND());insert into t1 values(9,RAND()*1000,RAND()*1000,RAND());insert into t1 values(8,RAND()*1000,RAND()*1000,RAND());insert into t1 values(7,RAND()*1000,RAND()*1000,RAND());insert into t1 values(6,RAND()*1000,RAND()*1000,RAND());insert into t1 values(5,RAND()*1000,RAND()*1000,RAND());insert into t1 values(4,RAND()*1000,RAND()*1000,RAND());insert into t1 values(3,RAND()*1000,RAND()*1000,RAND());insert into t1 values(2,RAND()*1000,RAND()*1000,RAND());insert into t1 values(1,RAND()*1000,RAND()*1000,RAND());alter table t1 enable keys;show keys from t1;Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Commentt1 0 n1 1 n1 A 10 NULL NULL BTREE t1 1 n1_2 1 n1 A 10 NULL NULL BTREE t1 1 n1_2 2 n2 A 10 NULL NULL YES BTREE t1 1 n1_2 3 n3 A 10 NULL NULL YES BTREE t1 1 n1_2 4 n4 A 10 NULL NULL YES BTREE t1 1 n2 1 n2 A 10 NULL NULL YES BTREE t1 1 n2 2 n3 A 10 NULL NULL YES BTREE t1 1 n2 3 n4 A 10 NULL NULL YES BTREE t1 1 n2 4 n1 A 10 NULL NULL BTREE t1 1 n3 1 n3 A 10 NULL NULL YES BTREE t1 1 n3 2 n4 A 10 NULL NULL YES BTREE t1 1 n3 3 n1 A 10 NULL NULL BTREE t1 1 n3 4 n2 A 10 NULL NULL YES BTREE t1 1 n4 1 n4 A 10 NULL NULL YES BTREE t1 1 n4 2 n1 A 10 NULL NULL BTREE t1 1 n4 3 n2 A 10 NULL NULL YES BTREE t1 1 n4 4 n3 A 10 NULL NULL YES BTREE drop table t1;create table t1 (i int unsigned not null auto_increment primary key);alter table t1 rename t2;alter table t2 rename t1, add c char(10) comment "no comment";show columns from t1;Field Type Null Key Default Extrai int(10) unsigned NO PRI NULL auto_incrementc char(10) YES NULL drop table t1;create table t1 (a int, b int);insert into t1 values(1,100), (2,100), (3, 100);insert into t1 values(1,99), (2,99), (3, 99);insert into t1 values(1,98), (2,98), (3, 98);insert into t1 values(1,97), (2,97), (3, 97);insert into t1 values(1,96), (2,96), (3, 96);insert into t1 values(1,95), (2,95), (3, 95);insert into t1 values(1,94), (2,94), (3, 94);insert into t1 values(1,93), (2,93), (3, 93);insert into t1 values(1,92), (2,92), (3, 92);insert into t1 values(1,91), (2,91), (3, 91);insert into t1 values(1,90), (2,90), (3, 90);insert into t1 values(1,89), (2,89), (3, 89);insert into t1 values(1,88), (2,88), (3, 88);insert into t1 values(1,87), (2,87), (3, 87);insert into t1 values(1,86), (2,86), (3, 86);insert into t1 values(1,85), (2,85), (3, 85);insert into t1 values(1,84), (2,84), (3, 84);insert into t1 values(1,83), (2,83), (3, 83);insert into t1 values(1,82), (2,82), (3, 82);insert into t1 values(1,81), (2,81), (3, 81);insert into t1 values(1,80), (2,80), (3, 80);insert into t1 values(1,79), (2,79), (3, 79);insert into t1 values(1,78), (2,78), (3, 78);insert into t1 values(1,77), (2,77), (3, 77);insert into t1 values(1,76), (2,76), (3, 76);insert into t1 values(1,75), (2,75), (3, 75);insert into t1 values(1,74), (2,74), (3, 74);insert into t1 values(1,73), (2,73), (3, 73);insert into t1 values(1,72), (2,72), (3, 72);insert into t1 values(1,71), (2,71), (3, 71);insert into t1 values(1,70), (2,70), (3, 70);insert into t1 values(1,69), (2,69), (3, 69);insert into t1 values(1,68), (2,68), (3, 68);insert into t1 values(1,67), (2,67), (3, 67);insert into t1 values(1,66), (2,66), (3, 66);insert into t1 values(1,65), (2,65), (3, 65);insert into t1 values(1,64), (2,64), (3, 64);insert into t1 values(1,63), (2,63), (3, 63);insert into t1 values(1,62), (2,62), (3, 62);insert into t1 values(1,61), (2,61), (3, 61);insert into t1 values(1,60), (2,60), (3, 60);insert into t1 values(1,59), (2,59), (3, 59);insert into t1 values(1,58), (2,58), (3, 58);insert into t1 values(1,57), (2,57), (3, 57);insert into t1 values(1,56), (2,56), (3, 56);insert into t1 values(1,55), (2,55), (3, 55);insert into t1 values(1,54), (2,54), (3, 54);insert into t1 values(1,53), (2,53), (3, 53);insert into t1 values(1,52), (2,52), (3, 52);insert into t1 values(1,51), (2,51), (3, 51);insert into t1 values(1,50), (2,50), (3, 50);insert into t1 values(1,49), (2,49), (3, 49);insert into t1 values(1,48), (2,48), (3, 48);insert into t1 values(1,47), (2,47), (3, 47);insert into t1 values(1,46), (2,46), (3, 46);insert into t1 values(1,45), (2,45), (3, 45);insert into t1 values(1,44), (2,44), (3, 44);insert into t1 values(1,43), (2,43), (3, 43);insert into t1 values(1,42), (2,42), (3, 42);insert into t1 values(1,41), (2,41), (3, 41);insert into t1 values(1,40), (2,40), (3, 40);insert into t1 values(1,39), (2,39), (3, 39);insert into t1 values(1,38), (2,38), (3, 38);insert into t1 values(1,37), (2,37), (3, 37);insert into t1 values(1,36), (2,36), (3, 36);insert into t1 values(1,35), (2,35), (3, 35);insert into t1 values(1,34), (2,34), (3, 34);insert into t1 values(1,33), (2,33), (3, 33);insert into t1 values(1,32), (2,32), (3, 32);insert into t1 values(1,31), (2,31), (3, 31);insert into t1 values(1,30), (2,30), (3, 30);insert into t1 values(1,29), (2,29), (3, 29);insert into t1 values(1,28), (2,28), (3, 28);insert into t1 values(1,27), (2,27), (3, 27);insert into t1 values(1,26), (2,26), (3, 26);insert into t1 values(1,25), (2,25), (3, 25);insert into t1 values(1,24), (2,24), (3, 24);insert into t1 values(1,23), (2,23), (3, 23);insert into t1 values(1,22), (2,22), (3, 22);insert into t1 values(1,21), (2,21), (3, 21);insert into t1 values(1,20), (2,20), (3, 20);insert into t1 values(1,19), (2,19), (3, 19);insert into t1 values(1,18), (2,18), (3, 18);insert into t1 values(1,17), (2,17), (3, 17);insert into t1 values(1,16), (2,16), (3, 16);insert into t1 values(1,15), (2,15), (3, 15);insert into t1 values(1,14), (2,14), (3, 14);insert into t1 values(1,13), (2,13), (3, 13);insert into t1 values(1,12), (2,12), (3, 12);insert into t1 values(1,11), (2,11), (3, 11);insert into t1 values(1,10), (2,10), (3, 10);insert into t1 values(1,9), (2,9), (3, 9);insert into t1 values(1,8), (2,8), (3, 8);insert into t1 values(1,7), (2,7), (3, 7);insert into t1 values(1,6), (2,6), (3, 6);insert into t1 values(1,5), (2,5), (3, 5);insert into t1 values(1,4), (2,4), (3, 4);insert into t1 values(1,3), (2,3), (3, 3);insert into t1 values(1,2), (2,2), (3, 2);insert into t1 values(1,1), (2,1), (3, 1);
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