I would like to know how many rows are in each table in my database. I've come so far as to having
select count(*) _tablename_;
However i would need to do that on each and every table - and there are a lot. What would me the best way to get a print-out with the table name and it's row count?
SELECT table_name, table_rows
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_SCHEMA = '<your db>';
I also hope you realise there's an error in your query: it's missing a FROM.
This following query will return number of rows in each table but it doesn't seem to return exact value all the time
SELECT table_name, table_rows
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_SCHEMA = '<your db>';
TABLE_ROWS: The number of table rows in the partition. For partitioned InnoDB tables, the row count given in the TABLE_ROWS column is only an estimated value used in SQL optimization, and may not always be exact...
for more https://dev.mysql.com/doc/mysql-infoschema-excerpt/5.5/en/partitions-table.html
In addition to SQL queries by others, one can also use Workbench GUI to get the row-counts of each table. To do this, Launch Workbench -> Connect to Db -> right click Db and select "Schema Inspector" (as in Screenshot below - I have highlighted the "Rows" column):
HTH.
Related
I am facing a problem in searching a particular table_name.
I have around 50 databases on the server and i wish to search a table_name say X is created in which all databases.
Is there any straight-forward to find the exact databases in which X table is found in MYSQL through phpMyAdmin.
Any help will be appreciated.
Thanks
You can query the information_schema database for this. The below query will return the names of all the databases, which contains the table your_table_name.
SELECT `TABLE_SCHEMA`
FROM `information_schema`.`TABLES`
WHERE `TABLE_NAME` = 'your_table_name'
I hope this is what you are looking for.
According to the MySQL documentation about information_schema database,
INFORMATION_SCHEMA provides access to database metadata.
Metadata is data about the data, such as the name of a database or
table, the data type of a column, or access privileges. Other terms
that sometimes are used for this information are data dictionary and
system catalog.
Please query the information_schema.TABLES with table_type='BASE TABLE' and providing the name of the table(table_name).
This query will give us all the tables with '<your_table_name>' in all the databases that are currently in our server.
Please change '<your_table_name>' as per your requirement.
SELECT TABLE_SCHEMA, TABLE_NAME
FROM `information_schema`.`TABLES`
where table_type='BASE TABLE'
and table_name = '<your_table_name>'
limit 100;
Is it possible to list all tables in a given MySQL database with the modification date in the right side?
I am looking for something like
SHOW TABLES FROM MY_DATABASE;
You can query the tables with information_schema.tables
select table_name,
coalesce(update_time, create_time) as last_modified
from information_schema.tables
Is there any way to know the time when last select statement has been performed on a table? I am using the InnoDB storage engine.
I have tried with the following query:
select update_time,table_name from information_schema.tables where table_schema='databasename';
..but I'm receiving NULL in the update_time column.
Unless you manually update a last_accessed-field on the table, my best bet would be to add query logging and parse the log-files.
I googled and found these relates questions:
When was the last time a mysql table was accessed?
How do you get the last access (and/or write) time of a MySQL database?
SELECT UPDATE_TIME
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_SCHEMA = 'dbname'
AND TABLE_NAME = 'tabname'`
I am trying to get a list of tables and their number of rows. I have been using this query:
SELECT TABLE_NAME, TABLE_ROWS
FROM INFORMATION_SCHEMA WHERE TABLE_SCHEMA = 'myDatabase'
I am finding this sometimes returns null. What I would like to do is catch this probably doing something similar to
IFNULL ( TABLE_ROWS, SELECT COUNT(*) FROM ????)
Only I'm not sure what I should enter for ????
how to make it dynamic based on the TABLE_NAME column?.
Edit: Additional information: I found that the 'tables' not displaying are actually views.
Might as well do
SHOW TABLE STATUS FROM YOUR_DATABASE;
It always return a column named as Rows which is number of rows in that table.
From the documentation:
The TABLE_ROWS column is NULL if the table is in the INFORMATION_SCHEMA database.
So, you will propably not need it.
Say if there is a database that has 200 tables, is there a quick way to see how many records are in each table, if possible, sorted by the number of records descendingly?
SELECT table_name,
table_rows
FROM `information_schema`.`tables`
WHERE table_schema = '<Your Database Name>'
ORDER BY table_rows DESC
Does show table status work for your problem? It has the row counts?