PostgreSQL的 - 錯誤查詢

Question

我有這個疑問：

SELECT DISTINCT par.id, par.title, cod.id AS id_codebook, cod.title AS title_codebook 
FROM catalog_parameter_codebook cod 
JOIN catalog_parameter par ON (par.id=cod.id_parameter) 
JOIN catalog_parameter_product_value_parameter_codebook_mm codmm ON (cod.id=codmm.id_parameter_codebook) 
JOIN catalog_parameter_product_value pv ON (pv.id=codmm.id_parameter_product_value) 
JOIN catalog_product p ON (p.id=pv.id_product) 
WHERE p.state=2 AND p.hidden=0 AND par.type=2 AND par.display_in_parameter_search=1 AND par.hidden=0 
ORDER BY par.sorting, cod.title 

，我得到這個錯誤：

LINE 8: ORDER BY par.sorting, cod.title

ERROR: for SELECT DISTINCT, ORDER BY expressions must appear in select list

我與PostgreSQL中的總的初學者。 謝謝。

Answer 1

的錯誤消息指出，par.sorting必須在選擇列表

如果您使用不同的或組，你被排序的所有列，必須在選擇列列表

SELECT DISTINCT par.id, par.title, cod.id AS id_codebook, cod.title AS title_codebook, par.sorting 
FROM catalog_parameter_codebook cod 
JOIN catalog_parameter par ON (par.id=cod.id_parameter) 
JOIN catalog_parameter_product_value_parameter_codebook_mm codmm ON (cod.id=codmm.id_parameter_codebook) 
JOIN catalog_parameter_product_value pv ON (pv.id=codmm.id_parameter_product_value) 
JOIN catalog_product p ON (p.id=pv.id_product) 
WHERE p.state=2 AND p.hidden=0 AND par.type=2 AND par.display_in_parameter_search=1 AND par.hidden=0 
ORDER BY par.sorting, cod.title