Function TestSqlRewrite

rel/sql_test.go:164–359

(t *testing.T)

}

func TestSqlRewrite(t *testing.T) {
	t.Parallel()
	/*
		SQL Re-writing is to take select statement with multiple sources (joins, sub-select)
		and rewrite these sub-statements/sources into standalone statements
		and prepare the column name, index mapping

		- Do we want to send the columns fully aliased?   ie
			SELECT name AS u.name, email as u.email, user_id as u.user_id FROM users
	*/
	s := `SELECT u.name, o.item_id, u.email, o.price
			FROM users AS u INNER JOIN orders AS o 
			ON u.user_id = o.user_id;`
	sql := parseOrPanic(t, s).(*rel.SqlSelect)
	err := sql.Finalize()
	assert.True(t, err == nil, "no error: %v", err)
	assert.True(t, len(sql.Columns) == 4, "has 4 cols: %v", len(sql.Columns))
	assert.True(t, len(sql.From) == 2, "has 2 sources: %v", len(sql.From))

	// Test the Left/Right column level parsing
	//  TODO:   This field should not be u.name?   sourcefield should be name right? as = u.name?
	col, _ := sql.Columns.ByName("u.name")
	assert.True(t, col.As == "u.name", "col.As=%s", col.As)
	left, right, ok := col.LeftRight()
	//u.Debugf("left=%v  right=%v  ok%v", left, right, ok)
	assert.True(t, left == "u" && right == "name" && ok == true)

	rw1 := sql.From[0].Rewrite(sql)
	assert.True(t, rw1 != nil, "should not be nil:")
	assert.True(t, len(rw1.Columns) == 3, "has 3 cols: %v", rw1.Columns.String())
	//u.Infof("SQL?: '%v'", rw1.String())
	assert.Equal(t, rw1.String(), "SELECT name, email, user_id FROM users", "%v", rw1.String())

	rw1 = sql.From[1].Rewrite(sql)
	assert.True(t, rw1 != nil, "should not be nil:")
	assert.True(t, len(rw1.Columns) == 3, "has 3 cols: %v", rw1.Columns.String())
	//u.Infof("SQL?: '%v'", rw1.String())
	assert.True(t, rw1.String() == "SELECT item_id, price, user_id FROM orders", "%v", rw1.String())

	// Do we change?
	//assert.Equal(t, sql.Columns.FieldNames(), []string{"user_id", "email", "item_id", "price"})

	s = `SELECT u.name, u.email, b.title
			FROM users AS u INNER JOIN blog AS b 
			ON u.name = b.author;`
	sql = parseOrPanic(t, s).(*rel.SqlSelect)
	assert.True(t, len(sql.Columns) == 3, "has 3 cols: %v", len(sql.Columns))
	assert.True(t, len(sql.From) == 2, "has 2 sources: %v", len(sql.From))
	rw1 = sql.From[0].Rewrite(sql)
	assert.True(t, rw1 != nil, "should not be nil:")
	assert.True(t, len(rw1.Columns) == 2, "has 2 cols: %v", rw1.Columns.String())
	//u.Infof("SQL?: '%v'", rw1.String())
	assert.True(t, rw1.String() == "SELECT name, email FROM users", "%v", rw1.String())
	jn := sql.From[0].JoinNodes()
	assert.True(t, len(jn) == 1, "%v", jn)
	assert.True(t, jn[0].String() == "name", "wanted 1 node %v", jn[0].String())
	cols := sql.From[0].UnAliasedColumns()
	assert.True(t, len(cols) == 2, "Should have 2: %#v", cols)