從postgreSQL查詢json對象

Question

我想在表格中的json對象的postgreSql中使用where條件。我需要這樣做，例如：我有一個表'測試'它有三列名稱（varchar），url（varchar），更多（json）。我需要檢索css21Colors = Purple的日期。 more是一個json類型，下面是更多字段的值。

請讓我知道同樣的查詢語法應該是什麼？

more = {"colorTree":{"Purple":[{"Spanish Violet":"#522173"}], 
"Brown":[{"Dark Puce":"#4e3347"}],"White":[{"White":"#ffffff"}], 
"Black":[{"Eerie Black":"#1d0d27"}],"Gray":[{"Rose Quartz":"#a091a4"}]}, 
"sizeoutscount":0,"css21Colors":{"Purple":69,"Brown":5,"White":4,"Black":17,"Gray":3}, 
"sizeins": [],"sizeinscount":0,"sizeouts":[],"allsizes":["8","10","16"], 
"css3Colors": {"Rose Quartz":3,"White":4,"Dark Puce":5,"Eerie Black":17,"Spanish 
Violet":69},"hexColors":{"#522173":69,"#4e3347":5,"#ffffff":4,"#1d0d27":17,"#a091a4":3}} 

Answer 1

SELECT more->'css21Colors'->'Purple' FROM test; 

此外，您可以查詢只包含關鍵的行。

SELECT 
    more->'css21Colors'->'Purple' 
FROM 
    test 
WHERE 
    (more->'css21Colors')::jsonb ? 'Purple'; 

注意切換到jsonb數據類型。