Rows

The number of rows. Some storage engines, such as MyISAM, store the exact count. For other storage engines, such as InnoDB, this value is an approximation, and may vary from the actual value by as much as 40 to 50%. In such cases, use SELECT COUNT(*) to obtain an accurate count.

Here is an example.

mysql> select count(*) from table;
+———-+
| count(*) |
+———-+
| 14828558 |
+———-+
1 row in set (39.94 sec)

#########
Now to make it interesting, I will to the show table status and your SQL statement and get different results from the count(*). (Note the “show table status” results match the output of your SQL statement, if I could execute them at identical seconds).
#########

mysql> SELECT concat(table_schema,’.',table_name),concat(round(table_rows/1000000,2),’M') rows,concat(round(data_length/(1024*1024*1024),2),’G') DATA,concat(round(index_length/(1024*1024*1024),2),’G') idx,concat(round((data_length+index_length)/(1024*1024*1024),2),’G') total_size,round(index_length/data_length,2) idxfrac FROM information_schema.TABLES ORDER BY data_length+index_length DESC LIMIT 10;
+———————————————-+——–+——-+——-+————+———+
| concat(table_schema,’.',table_name) | rows | DATA | idx | total_size | idxfrac |
+———————————————-+——–+——-+——-+————+———+
| database.table | 14.73M | 2.08G | 0.00G | 2.08G | 0.00 |
+———————————————-+——–+——-+——-+————+———+
10 rows in set (0.15 sec)

mysql> show table status like ‘table’ \G
*************************** 1. row ***************************
Name: table
Engine: InnoDB
Version: 10
Row_format: Compact
Rows: 14898977
Avg_row_length: 150
Data_length: 2237661184
Max_data_length: 0
Index_length: 0
Data_free: 0
Auto_increment: NULL
Create_time: 2008-10-01 09:38:00
Update_time: NULL
Check_time: NULL
Collation: latin1_swedish_ci
Checksum: NULL
Create_options:
Comment: InnoDB free: 4021248 kB
1 row in set (0.06 sec)

########
I have ran your query and the show table status query yet again and get new values that are not consistent with “select count(*) from “.
########

+———————————————-+——–+——-+——-+————+———+
| concat(table_schema,’.',table_name) | rows | DATA | idx | total_size | idxfrac |
+———————————————-+——–+——-+——-+————+———+
| database.table | 15.00M | 2.08G | 0.00G | 2.08G | 0.00 |
+———————————————-+——–+——-+——-+————+———+

mysql> show table status like ‘table’ \G
*************************** 1. row ***************************
Name: table
Engine: InnoDB
Version: 10
Row_format: Compact
Rows: 15120698
Avg_row_length: 147
Data_length: 2237661184
Max_data_length: 0
Index_length: 0
Data_free: 0
Auto_increment: NULL
Create_time: 2008-10-01 09:38:00
Update_time: NULL
Check_time: NULL
Collation: latin1_swedish_ci
Checksum: NULL
Create_options:
Comment: InnoDB free: 4021248 kB
1 row in set (0.02 sec)

mysql> select count(*) from table;
+———-+
| count(*) |
+———-+
| 14828945 |
+———-+
1 row in set (44.33 sec)

btw, a tips:
If you want to show tables only in a certain database, add a WHERE clause in the SQL
WHERE table_schema = ‘db_name’