Count a rows from a single table.
select count(*) from myTableName;
View rows counts from all tables as reported by the information schema, this is not always up to date and might not give back exact row counts.
SELECT table_name, table_rows FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = 'myDatabaseName';
Another option to get exact row counts is to use this query:
select concat( 'select "', table_name, '" as table_name, count(*) as exact_row_count from ', table_schema, '.', table_name, ' union ' ) from INFORMATION_SCHEMA.TABLES where table_schema = 'myDatabaseName';