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What is a Join? The SELECT queries shown thus far in this training guide retrieve information from a single table at a time. However, not all questions can be answered using just one table. When it's necessary to draw on information that is stored in multiple tables, use a join condition—an operation that produces a result by combining (joining) information in one table with information in another. The contents of two original tables are shown below. These tables can be joined together using a SELECT query which retrieves data from more than one table at a time. table1 table2 +----+----+ | i1 | c1 | +----+----+ | 1 | a | | 2 | b | | 3 | c | +----+----+ 3 rows in set (#.## sec) +----+----+ | i2 | c2 | +----+----+ | 2 | c | | 3 | b | | 4 | a | +----+----+ 3 rows in set (#.## sec) mysql> SELECT * FROM table1 JOIN table2; +----+----+----+----+ | i1 | c1 | i2 | c2 | +----+----+----+----+ | 1 | a | 2 | c | | 2 | b | 2 | c |