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Spec-Zone .ru
спецификации, руководства, описания, API
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The TABLES table provides
information about tables in databases.
INFORMATION_SCHEMA Name |
SHOW Name
|
Remarks |
|---|---|---|
TABLE_CATALOG |
def |
|
TABLE_SCHEMA |
Table_... |
|
TABLE_NAME |
Table_... |
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TABLE_TYPE |
||
ENGINE |
Engine |
MySQL extension |
VERSION |
Version |
The version number of the table's .frm file, MySQLextension |
ROW_FORMAT |
Row_format |
MySQL extension |
TABLE_ROWS |
Rows |
MySQL extension |
AVG_ROW_LENGTH |
Avg_row_length |
MySQL extension |
DATA_LENGTH |
Data_length |
MySQL extension |
MAX_DATA_LENGTH |
Max_data_length |
MySQL extension |
INDEX_LENGTH |
Index_length |
MySQL extension |
DATA_FREE |
Data_free |
MySQL extension |
AUTO_INCREMENT |
Auto_increment |
MySQL extension |
CREATE_TIME |
Create_time |
MySQL extension |
UPDATE_TIME |
Update_time |
MySQL extension |
CHECK_TIME |
Check_time |
MySQL extension |
TABLE_COLLATION |
Collation |
MySQL extension |
CHECKSUM |
Checksum |
MySQL extension |
CREATE_OPTIONS |
Create_options |
MySQL extension |
TABLE_COMMENT |
Comment |
MySQL extension |
Notes:
TABLE_SCHEMA and TABLE_NAME are a single field in a SHOW display, for example Table_in_db1.
TABLE_TYPE should be BASE
TABLE or VIEW. Currently, the TABLES table does not list TEMPORARY tables.
For partitioned tables, the ENGINE column shows the
name of the storage engine used by all partitions. (Previously, this column showed PARTITION for such tables.)
The TABLE_ROWS column is NULL if the table is in the INFORMATION_SCHEMA
database.
For InnoDB tables, the
row count is only a rough estimate used in SQL optimization. (This is also true if the InnoDB table is
partitioned.)
The DATA_FREE column shows the free space in bytes for
InnoDB tables.
We have nothing for the table's default character set. TABLE_COLLATION
is close, because collation names begin with a character set name.
The CREATE_OPTIONS column shows partitioned
if the table is partitioned.
Beginning with MySQL 5.7.2, UPDATE_TIME displays a
timestamp value for the last UPDATE,
INSERT, or DELETE
performed on InnoDB tables. Previously, UPDATE_TIME displayed a NULL value for InnoDB tables. For MVCC, the timestamp value reflects the COMMIT time, which is considered the last update time. Timestamps are
not persisted when the server is restarted or when the table is evicted from the InnoDB
data dictionary cache.
The following statements are equivalent:
SELECT table_name FROM INFORMATION_SCHEMA.TABLES WHERE table_schema = 'db_name' [AND table_name LIKE 'wild']SHOW TABLES FROMdb_name[LIKE 'wild']