1
DROP TABLE IF EXISTS t0,t1,t2,t3,t4,t5;
2
select * from information_schema.SCHEMATA where schema_name > 'm';
3
CATALOG_NAME SCHEMA_NAME DEFAULT_CHARACTER_SET_NAME DEFAULT_COLLATION_NAME SQL_PATH
4
NULL mysql utf8 utf8_general_ci NULL
5
NULL test utf8 utf8_general_ci NULL
6
select schema_name from information_schema.schemata;
11
show databases like 't%';
19
create database mysqltest;
20
create table mysqltest.t1(a int, b VARCHAR(30), KEY string_data (b));
21
create table test.t2(a int);
22
create table t3(a int, KEY a_data (a));
23
create table mysqltest.t4(a int);
24
create table t5 (id int auto_increment primary key);
25
insert into t5 values (10);
26
select table_name from information_schema.TABLES
27
where table_schema = "mysqltest" and table_name like "t%";
31
select * from information_schema.STATISTICS where TABLE_SCHEMA = "mysqltest";
32
TABLE_CATALOG TABLE_SCHEMA TABLE_NAME NON_UNIQUE INDEX_SCHEMA INDEX_NAME SEQ_IN_INDEX COLUMN_NAME COLLATION CARDINALITY SUB_PART PACKED NULLABLE INDEX_TYPE COMMENT INDEX_COMMENT
33
NULL mysqltest t1 1 mysqltest string_data 1 b A 0 NULL NULL YES BTREE
34
show tables like 't%';
39
show full columns from t3 like "a%";
40
Field Type Collation Null Key Default Extra Privileges Comment
41
a int NULL YES MUL NULL #
42
select * from information_schema.COLUMNS where table_name="t1"
44
TABLE_CATALOG TABLE_SCHEMA TABLE_NAME COLUMN_NAME ORDINAL_POSITION COLUMN_DEFAULT IS_NULLABLE DATA_TYPE CHARACTER_MAXIMUM_LENGTH CHARACTER_OCTET_LENGTH NUMERIC_PRECISION NUMERIC_SCALE CHARACTER_SET_NAME COLLATION_NAME COLUMN_TYPE COLUMN_KEY EXTRA PRIVILEGES COLUMN_COMMENT STORAGE FORMAT
45
NULL mysqltest t1 a 1 NULL YES int NULL NULL 10 0 NULL NULL int Default Default
46
select table_name, column_name, privileges from information_schema.columns
47
where table_schema = 'mysqltest' and table_name = 't1';
48
table_name column_name privileges
51
show columns from mysqltest.t1;
52
Field Type Null Key Default Extra
54
b varchar(30) YES MUL NULL
55
drop tables mysqltest.t4, mysqltest.t1, t2, t3, t5;
56
drop database mysqltest;
57
select * from information_schema.CHARACTER_SETS
58
where CHARACTER_SET_NAME like 'latin1%';
59
CHARACTER_SET_NAME DEFAULT_COLLATE_NAME DESCRIPTION MAXLEN
60
select * from information_schema.COLLATIONS
61
where COLLATION_NAME like 'latin1%';
62
COLLATION_NAME CHARACTER_SET_NAME ID IS_DEFAULT IS_COMPILED SORTLEN
63
select * from information_schema.COLLATION_CHARACTER_SET_APPLICABILITY
64
where COLLATION_NAME like 'latin1%';
65
COLLATION_NAME CHARACTER_SET_NAME
66
select * from information_schema.table_names;
67
ERROR 42S02: Unknown table 'table_names' in information_schema
68
select column_type from information_schema.columns
69
where table_schema="information_schema" and table_name="COLUMNS" and
70
(column_name="character_set_name" or column_name="collation_name");
74
select TABLE_ROWS from information_schema.tables where
75
table_schema="information_schema" and table_name="COLUMNS";
78
select table_type from information_schema.tables
79
where table_schema="mysql" and table_name="user";
81
show global status like "Threads_running";
84
select table_schema,table_name, column_name from
85
information_schema.columns
86
where data_type = 'longtext';
87
table_schema table_name column_name
88
select table_name, column_name, data_type from information_schema.columns
89
where data_type = 'datetime';
90
table_name column_name data_type
91
TABLES CREATE_TIME datetime
92
TABLES UPDATE_TIME datetime
93
TABLES CHECK_TIME datetime
94
INNODB_TRX trx_started datetime
95
INNODB_TRX trx_wait_started datetime
96
SELECT COUNT(*) FROM INFORMATION_SCHEMA.TABLES A
98
(SELECT * FROM INFORMATION_SCHEMA.COLUMNS B
99
WHERE A.TABLE_SCHEMA = B.TABLE_SCHEMA
100
AND A.TABLE_NAME = B.TABLE_NAME);
107
x_decimal DECIMAL(5,3),
108
x_numeric NUMERIC(5,3),
111
x_double_precision DOUBLE PRECISION );
112
SELECT COLUMN_NAME, CHARACTER_MAXIMUM_LENGTH, CHARACTER_OCTET_LENGTH
113
FROM INFORMATION_SCHEMA.COLUMNS
114
WHERE TABLE_NAME= 't1';
115
COLUMN_NAME CHARACTER_MAXIMUM_LENGTH CHARACTER_OCTET_LENGTH
123
x_double_precision NULL NULL
125
SELECT table_schema, count(*) FROM information_schema.TABLES
126
WHERE table_name NOT LIKE 'ndb_%' AND table_name NOT LIKE 'falcon%' GROUP BY TABLE_SCHEMA;
127
table_schema count(*)
128
information_schema 23
129
show create database information_schema;
130
Database Create Database
131
information_schema CREATE DATABASE `information_schema`
132
create table t1(f1 LONGBLOB, f2 LONGTEXT);
133
select column_name,data_type,CHARACTER_OCTET_LENGTH,
134
CHARACTER_MAXIMUM_LENGTH
135
from information_schema.columns
136
where table_name='t1';
137
column_name data_type CHARACTER_OCTET_LENGTH CHARACTER_MAXIMUM_LENGTH
138
f1 blob 4294967295 4294967295
139
f2 text 4294967295 4294967295
141
create table t1(f1 int, f2 int, f3 BIGINT, f4 int,
142
f5 BIGINT, f6 int, f7 int);
143
select column_name, NUMERIC_PRECISION, NUMERIC_SCALE
144
from information_schema.columns
145
where table_name='t1';
146
column_name NUMERIC_PRECISION NUMERIC_SCALE
155
create table t1 (a int not null, b int);
156
use information_schema;
157
select column_name, column_default from columns
158
where table_schema='test' and table_name='t1';
159
column_name column_default
163
show columns from t1;
164
Field Type Null Key Default Extra
168
alter database information_schema;
169
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your Drizzle server version for the right syntax to use near '' at line 1
170
drop database information_schema;
171
ERROR 42000: Access denied for user ''@'' to database 'information_schema'
172
drop table information_schema.tables;
173
ERROR 42000: Access denied for user ''@'' to database 'information_schema'
174
alter table information_schema.tables;
175
ERROR 42000: Access denied for user ''@'' to database 'information_schema'
176
use information_schema;
177
create temporary table schemata(f1 char(10));
178
ERROR 42000: Access denied for user ''@'' to database 'information_schema'
180
create table t1(id int);
181
insert into t1(id) values (1);
182
select 1 from (select 1 from test.t1) a;
185
use information_schema;
186
select 1 from (select 1 from test.t1) a;
191
create temporary table t1(f1 int, index(f1));
192
show columns from t1;
193
Field Type Null Key Default Extra
196
Field Type Null Key Default Extra
198
show indexes from t1;
199
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment Index_Comment
200
t1 1 f1 1 f1 A 0 NULL NULL YES BTREE
202
create table t1(f1 varbinary(32), f2 varbinary(64));
203
select character_maximum_length, character_octet_length
204
from information_schema.columns where table_name='t1';
205
character_maximum_length character_octet_length
209
select column_type, group_concat(table_schema, '.', table_name), count(*) as num
210
from information_schema.columns where
211
table_schema='information_schema' and
212
(column_type = 'varchar(7)' or column_type = 'varchar(20)'
213
or column_type = 'varchar(27)')
214
group by column_type order by num;
215
column_type group_concat(table_schema, '.', table_name) num
216
varchar(20) information_schema.PLUGINS 1
217
varchar(27) information_schema.COLUMNS 1
218
create table t1(f1 char(1) not null, f2 char(9) not null);
219
select CHARACTER_MAXIMUM_LENGTH, CHARACTER_OCTET_LENGTH from
220
information_schema.columns where table_schema='test' and table_name = 't1';
221
CHARACTER_MAXIMUM_LENGTH CHARACTER_OCTET_LENGTH
226
create table t1(f1 char(5));
227
create table t2(f1 char(5));
228
select concat(@a, table_name), @a, table_name
229
from information_schema.tables where table_schema = 'test';
230
concat(@a, table_name) @a table_name
234
SELECT t.table_name, c1.column_name
235
FROM information_schema.tables t
237
information_schema.columns c1
238
ON t.table_schema = c1.table_schema AND
239
t.table_name = c1.table_name
240
WHERE t.table_schema = 'information_schema' AND
241
c1.ordinal_position =
242
( SELECT COALESCE(MIN(c2.ordinal_position),1)
243
FROM information_schema.columns c2
244
WHERE c2.table_schema = t.table_schema AND
245
c2.table_name = t.table_name AND
246
c2.column_name LIKE '%SCHEMA%'
248
AND t.table_name NOT LIKE 'falcon%';
249
table_name column_name
250
CHARACTER_SETS CHARACTER_SET_NAME
251
COLLATIONS COLLATION_NAME
252
COLLATION_CHARACTER_SET_APPLICABILITY COLLATION_NAME
254
GLOBAL_STATUS VARIABLE_NAME
255
GLOBAL_VARIABLES VARIABLE_NAME
256
KEY_COLUMN_USAGE CONSTRAINT_SCHEMA
259
REFERENTIAL_CONSTRAINTS CONSTRAINT_SCHEMA
261
SESSION_STATUS VARIABLE_NAME
262
SESSION_VARIABLES VARIABLE_NAME
263
STATISTICS TABLE_SCHEMA
265
TABLE_CONSTRAINTS CONSTRAINT_SCHEMA
267
INNODB_CMP_RESET page_size
268
INNODB_CMPMEM page_size
269
INNODB_CMPMEM_RESET page_size
270
INNODB_LOCK_WAITS requesting_trx_id
273
SELECT t.table_name, c1.column_name
274
FROM information_schema.tables t
276
information_schema.columns c1
277
ON t.table_schema = c1.table_schema AND
278
t.table_name = c1.table_name
279
WHERE t.table_schema = 'information_schema' AND
280
c1.ordinal_position =
281
( SELECT COALESCE(MIN(c2.ordinal_position),1)
282
FROM information_schema.columns c2
283
WHERE c2.table_schema = 'information_schema' AND
284
c2.table_name = t.table_name AND
285
c2.column_name LIKE '%SCHEMA%'
287
AND t.table_name NOT LIKE 'falcon%';
288
table_name column_name
289
CHARACTER_SETS CHARACTER_SET_NAME
290
COLLATIONS COLLATION_NAME
291
COLLATION_CHARACTER_SET_APPLICABILITY COLLATION_NAME
293
GLOBAL_STATUS VARIABLE_NAME
294
GLOBAL_VARIABLES VARIABLE_NAME
295
KEY_COLUMN_USAGE CONSTRAINT_SCHEMA
298
REFERENTIAL_CONSTRAINTS CONSTRAINT_SCHEMA
300
SESSION_STATUS VARIABLE_NAME
301
SESSION_VARIABLES VARIABLE_NAME
302
STATISTICS TABLE_SCHEMA
304
TABLE_CONSTRAINTS CONSTRAINT_SCHEMA
306
INNODB_CMP_RESET page_size
307
INNODB_CMPMEM page_size
308
INNODB_CMPMEM_RESET page_size
309
INNODB_LOCK_WAITS requesting_trx_id
312
SELECT MAX(table_name) FROM information_schema.tables;
315
SELECT table_name from information_schema.tables
316
WHERE table_name=(SELECT MAX(table_name)
317
FROM information_schema.tables);
320
create table t1 (f1 int);
321
create table t2 (f1 int, f2 int);
322
select table_name from information_schema.tables
323
where table_schema = 'test' and table_name not in
324
(select table_name from information_schema.columns
325
where table_schema = 'test' and column_name = 'f3');
330
select 1 as f1 from information_schema.tables where "CHARACTER_SETS"=
331
(select cast(table_name as char) from information_schema.tables
332
order by table_name limit 1) limit 1;
335
select t.table_name, group_concat(t.table_schema, '.', t.table_name),
337
from information_schema.tables t
338
inner join information_schema.columns c1
339
on t.table_schema = c1.table_schema AND t.table_name = c1.table_name
340
where t.table_schema = 'information_schema' AND
341
t.table_name not like 'falcon%' AND
342
c1.ordinal_position =
343
(select isnull(c2.column_type) -
344
isnull(group_concat(c2.table_schema, '.', c2.table_name)) +
346
from information_schema.columns c2 where
347
c2.table_schema='information_schema' and
348
(c2.column_type = 'varchar(7)' or c2.column_type = 'varchar(20)')
349
group by c2.column_type order by num limit 1)
350
group by t.table_name order by num1, t.table_name;
351
table_name group_concat(t.table_schema, '.', t.table_name) num1
352
CHARACTER_SETS information_schema.CHARACTER_SETS 1
353
COLLATIONS information_schema.COLLATIONS 1
354
COLLATION_CHARACTER_SET_APPLICABILITY information_schema.COLLATION_CHARACTER_SET_APPLICABILITY 1
355
COLUMNS information_schema.COLUMNS 1
356
GLOBAL_STATUS information_schema.GLOBAL_STATUS 1
357
GLOBAL_VARIABLES information_schema.GLOBAL_VARIABLES 1
358
INNODB_CMP information_schema.INNODB_CMP 1
359
INNODB_CMPMEM information_schema.INNODB_CMPMEM 1
360
INNODB_CMPMEM_RESET information_schema.INNODB_CMPMEM_RESET 1
361
INNODB_CMP_RESET information_schema.INNODB_CMP_RESET 1
362
INNODB_LOCKS information_schema.INNODB_LOCKS 1
363
INNODB_LOCK_WAITS information_schema.INNODB_LOCK_WAITS 1
364
INNODB_TRX information_schema.INNODB_TRX 1
365
KEY_COLUMN_USAGE information_schema.KEY_COLUMN_USAGE 1
366
PLUGINS information_schema.PLUGINS 1
367
PROCESSLIST information_schema.PROCESSLIST 1
368
REFERENTIAL_CONSTRAINTS information_schema.REFERENTIAL_CONSTRAINTS 1
369
SCHEMATA information_schema.SCHEMATA 1
370
SESSION_STATUS information_schema.SESSION_STATUS 1
371
SESSION_VARIABLES information_schema.SESSION_VARIABLES 1
372
STATISTICS information_schema.STATISTICS 1
373
TABLES information_schema.TABLES 1
374
TABLE_CONSTRAINTS information_schema.TABLE_CONSTRAINTS 1
376
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your Drizzle server version for the right syntax to use near '' at line 1
378
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your Drizzle server version for the right syntax to use near '' at line 1
381
f2 varchar(50) not null,
382
f3 varchar(50) default '',
383
f4 varchar(50) default NULL,
385
f6 bigint not null default 10,
386
f7 datetime not null,
387
f8 datetime default '2006-01-01'
389
select column_default from information_schema.columns where table_name= 't1';
399
show columns from t1;
400
Field Type Null Key Default Extra
401
f1 varchar(50) YES NULL
402
f2 varchar(50) NO NULL
404
f4 varchar(50) YES NULL
408
f8 datetime YES 2006-01-01 00:00:00
410
show fields from information_schema.table_names;
411
ERROR 42S02: Unknown table 'table_names' in information_schema
412
show keys from information_schema.table_names;
413
ERROR 42S02: Unknown table 'table_names' in information_schema
414
SET max_heap_table_size = DEFAULT;
417
SELECT SCHEMA_NAME FROM INFORMATION_SCHEMA.SCHEMATA
418
WHERE SCHEMA_NAME ='information_schema';
421
SELECT TABLE_COLLATION FROM INFORMATION_SCHEMA.TABLES
422
WHERE TABLE_SCHEMA='mysql' and TABLE_NAME= 'db';
424
select * from information_schema.columns where table_schema = NULL;
425
TABLE_CATALOG TABLE_SCHEMA TABLE_NAME COLUMN_NAME ORDINAL_POSITION COLUMN_DEFAULT IS_NULLABLE DATA_TYPE CHARACTER_MAXIMUM_LENGTH CHARACTER_OCTET_LENGTH NUMERIC_PRECISION NUMERIC_SCALE CHARACTER_SET_NAME COLLATION_NAME COLUMN_TYPE COLUMN_KEY EXTRA PRIVILEGES COLUMN_COMMENT STORAGE FORMAT
426
select * from `information_schema`.`COLUMNS` where `TABLE_NAME` = NULL;
427
TABLE_CATALOG TABLE_SCHEMA TABLE_NAME COLUMN_NAME ORDINAL_POSITION COLUMN_DEFAULT IS_NULLABLE DATA_TYPE CHARACTER_MAXIMUM_LENGTH CHARACTER_OCTET_LENGTH NUMERIC_PRECISION NUMERIC_SCALE CHARACTER_SET_NAME COLLATION_NAME COLUMN_TYPE COLUMN_KEY EXTRA PRIVILEGES COLUMN_COMMENT STORAGE FORMAT
428
select * from `information_schema`.`KEY_COLUMN_USAGE` where `TABLE_SCHEMA` = NULL;
429
CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME TABLE_CATALOG TABLE_SCHEMA TABLE_NAME COLUMN_NAME ORDINAL_POSITION POSITION_IN_UNIQUE_CONSTRAINT REFERENCED_TABLE_SCHEMA REFERENCED_TABLE_NAME REFERENCED_COLUMN_NAME
430
select * from `information_schema`.`KEY_COLUMN_USAGE` where `TABLE_NAME` = NULL;
431
CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME TABLE_CATALOG TABLE_SCHEMA TABLE_NAME COLUMN_NAME ORDINAL_POSITION POSITION_IN_UNIQUE_CONSTRAINT REFERENCED_TABLE_SCHEMA REFERENCED_TABLE_NAME REFERENCED_COLUMN_NAME
432
select * from `information_schema`.`REFERENTIAL_CONSTRAINTS` where `CONSTRAINT_SCHEMA` = NULL;
433
CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME UNIQUE_CONSTRAINT_CATALOG UNIQUE_CONSTRAINT_SCHEMA UNIQUE_CONSTRAINT_NAME MATCH_OPTION UPDATE_RULE DELETE_RULE TABLE_NAME REFERENCED_TABLE_NAME
434
select * from `information_schema`.`REFERENTIAL_CONSTRAINTS` where `TABLE_NAME` = NULL;
435
CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME UNIQUE_CONSTRAINT_CATALOG UNIQUE_CONSTRAINT_SCHEMA UNIQUE_CONSTRAINT_NAME MATCH_OPTION UPDATE_RULE DELETE_RULE TABLE_NAME REFERENCED_TABLE_NAME
436
select * from information_schema.schemata where schema_name = NULL;
437
CATALOG_NAME SCHEMA_NAME DEFAULT_CHARACTER_SET_NAME DEFAULT_COLLATION_NAME SQL_PATH
438
select * from `information_schema`.`STATISTICS` where `TABLE_SCHEMA` = NULL;
439
TABLE_CATALOG TABLE_SCHEMA TABLE_NAME NON_UNIQUE INDEX_SCHEMA INDEX_NAME SEQ_IN_INDEX COLUMN_NAME COLLATION CARDINALITY SUB_PART PACKED NULLABLE INDEX_TYPE COMMENT INDEX_COMMENT
440
select * from `information_schema`.`STATISTICS` where `TABLE_NAME` = NULL;
441
TABLE_CATALOG TABLE_SCHEMA TABLE_NAME NON_UNIQUE INDEX_SCHEMA INDEX_NAME SEQ_IN_INDEX COLUMN_NAME COLLATION CARDINALITY SUB_PART PACKED NULLABLE INDEX_TYPE COMMENT INDEX_COMMENT
442
select * from information_schema.tables where table_schema = NULL;
443
TABLE_CATALOG TABLE_SCHEMA TABLE_NAME TABLE_TYPE ENGINE VERSION ROW_FORMAT TABLE_ROWS AVG_ROW_LENGTH DATA_LENGTH MAX_DATA_LENGTH INDEX_LENGTH DATA_FREE AUTO_INCREMENT CREATE_TIME UPDATE_TIME CHECK_TIME TABLE_COLLATION CHECKSUM CREATE_OPTIONS TABLE_COMMENT
444
select * from information_schema.tables where table_catalog = NULL;
445
TABLE_CATALOG TABLE_SCHEMA TABLE_NAME TABLE_TYPE ENGINE VERSION ROW_FORMAT TABLE_ROWS AVG_ROW_LENGTH DATA_LENGTH MAX_DATA_LENGTH INDEX_LENGTH DATA_FREE AUTO_INCREMENT CREATE_TIME UPDATE_TIME CHECK_TIME TABLE_COLLATION CHECKSUM CREATE_OPTIONS TABLE_COMMENT
446
select * from information_schema.tables where table_name = NULL;
447
TABLE_CATALOG TABLE_SCHEMA TABLE_NAME TABLE_TYPE ENGINE VERSION ROW_FORMAT TABLE_ROWS AVG_ROW_LENGTH DATA_LENGTH MAX_DATA_LENGTH INDEX_LENGTH DATA_FREE AUTO_INCREMENT CREATE_TIME UPDATE_TIME CHECK_TIME TABLE_COLLATION CHECKSUM CREATE_OPTIONS TABLE_COMMENT
448
select * from `information_schema`.`TABLE_CONSTRAINTS` where `TABLE_SCHEMA` = NULL;
449
CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME TABLE_SCHEMA TABLE_NAME CONSTRAINT_TYPE
450
select * from `information_schema`.`TABLE_CONSTRAINTS` where `TABLE_NAME` = NULL;
451
CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME TABLE_SCHEMA TABLE_NAME CONSTRAINT_TYPE