在下列SQL语句中，哪个是检索无重复行的正确方法？( )
SELECT * FROM TableA WHERE ColumnX IS DISTINCT;
SELECT UNIQUE * FROM TableA WHERE ColumnX="SomeValue";
SELECT DISTINCT * FROM TableA WHERE ColumnX="SomeValue";
SELECT * FROM TableA WHERE ColumnX=UNIQUE("SomeValue");
SELECT * FROM TableA WHERE ColumnX IS UNIQUE;
