php - Should table names be prefixed with the database name and period when using MySQL/PDO? -
the vast majority of queries i've seen have database name followed period before table name. example: select * mydatabase.mytable; however, seems work well: select * mytable; is there reason have mydatabase. before each table name? i using mysql via pdo in php. is there reason have mydatabase. before each table name yes, if performing cross database query ; accessing , joining tables different database. example below db1 , db2 different databases. select t1.*,t2.some_column db1.table1 t1 inner join db2.table2 t2 on t1.some_id_column = t2.some_id_column; but if accessing tables same database , running query against database no need specifying qualified name ( db_name.schema_name.table_name )