Oracle左，外、右

/** left (outer) join */

/** Standard SQL Syntax */

select*from a leftouterjoin b on a.id = b.id;

/** Oracle SQL Syntax */

select*from a, b where a.id = b.id(+);

/** right (outer) join */

/** Standard SQL Syntax */

select*from a rightouterjoin b on a.id = b.id;

/** Oracle SQL Syntax */

select*from a, b where a.id(+) = b.id;

/** (inner) join */

/** Standard SQL Syntax */

select*from a innerjoin b on a.id = b.id;

/** Oracle SQL Syntax */

select*from a, b where a.id = b.id;

/** (full) join */

/** Standard SQL Syntax */

select*from a fulljoin b on a.id = b.id;

/** Oracle SQL Syntax */

select*from a, b where a.id = b.id(+)

union

select*from a, b where a.id(+) = b.id;