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The SELECT statement has many optional clauses:
* <code>SELECT</code> clause is the list of [[column (database)|columns]] or SQL expressions that must be returned by the query. This is approximately the [[relational algebra]] [[Projection_(relational_algebra)|projection]] operation.
* <code>[[Alias (SQL)|AS]]</code> optionally provides an alias for each column or expression in the <code>SELECT</code> clause. This is the relational algebra [[Rename_(relational_algebra)|rename]] operation.
* <code>[[From (SQL)|FROM]]</code> specifies from which table to get the data.<ref>Omitting FROM clause isn't standard, but allowed by most major DBMSes.</ref>
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