text: -- collate4.test
  -- 
  -- execsql {
  --     CREATE TABLE collate4t2(
  --       a COLLATE NOCASE, 
  --       b COLLATE TEXT, 
  --       PRIMARY KEY(a, b)
  --     );
  --     INSERT INTO collate4t2 VALUES( 'a', 'a' );
  --     INSERT INTO collate4t2 VALUES( NULL, NULL );
  --     INSERT INTO collate4t2 VALUES( 'B', 'B' );
  -- }
  CREATE TABLE collate4t2(
  a COLLATE NOCASE, 
  b COLLATE TEXT, 
  PRIMARY KEY(a, b)
  );
  INSERT INTO collate4t2 VALUES( 'a', 'a' );
  INSERT INTO collate4t2 VALUES( NULL, NULL );
  INSERT INTO collate4t2 VALUES( 'B', 'B' );