Select (SQL)

A SELECT statement in SQL returns a result set of records from one of more tables.

Examples

Table "T" Query Result

C1	C2
1	a
2	b

SELECT * FROM T;

C1	C2
1	a
2	b

C1	C2
1	a
2	b

SELECT C1 FROM T;

C1
1
2

C1	C2
1	a
2	b

SELECT * FROM T WHERE C1 = 1;

C1	C2
1	a

Given a table T, the query SELECT * FROM T; will result in all the elements of all the rows of the table being shown.

With the same table, the query SELECT C1 FROM T; will result in the elements from the column C1 of all the rows of the table being shown — in Relational algebra terms, a projection will be performed.

With the same table, the query SELECT * FROM T WHERE C1 = 1; will result in all the elements of all the rows where the value of column C1 is '1' being shown — in Relational algebra terms, a selection will be performed, because of the WHERE keyword.