1

我将数据作为 jsonb 存储在 Postgres 12 表中，jsonb 的结构在数组内部有一个数组。

如何从嵌套数组中获取值？我可以从一级数组中获取值，但不能从二级数组中获取值。

这是 json 的简化示例

{
    "id": 1,
    "external_order_id": {
        "id": "2"
    },
    "customer": {
        "external_customer_id": {
            "id": "3"
        }
    },
    "line_items": [
        {
            "sku": "SKU-1",
            "properties": [
                {
                    "name": "colour",
                    "value": "red"
                },
                {
                    "name": "size",
                    "value": "large"
                }
            ],
            "external_product_id": {
                "id": "4"
            },
            "external_variant_id": {
                "id": "5"
            }
        },
        {
            "sku": "SKU-2",
            "properties": [
                {
                    "name": "colour",
                    "value": "black"
                },
                {
                    "name": "size",
                    "value": "small"
                }
            ],
            "external_product_id": {
                "id": "8"
            },
            "external_variant_id": {
                "id": "9"
            }
        }
    ]
}

使用带有 LATERAL 和 CROSS JOIN LATERAL 的 jsonb_to_record 和 jsonb_to_recordset，我能够从节点和第一级数组中获取值

WITH data(content) AS ( VALUES
  ('{
    "id": 1,
         "external_order_id": {
        "id": "2"
    },
    "customer": {
        
        "external_customer_id": {
            "id": "3"
        }
    },
    "line_items": [
        {
            "sku": "SKU-1",
            "properties": [
                {
                    "name": "colour",
                    "value": "red"
                },
                {
                    "name": "size",
                    "value": "large"
                }
            ],
            "external_product_id": {
                "id": "4"
            },
            "external_variant_id": {
                "id": "5"
            }
        },
                {
            "sku": "SKU-2",
            "properties": [
                {
                    "name": "colour",
                    "value": "black"
                },
                {
                    "name": "size",
                    "value": "small"
                }
            ],
            "external_product_id": {
                "id": "8"
            },
            "external_variant_id": {
                "id": "9"
            }
        }
    ]
   
}'::jsonb)
)
select ord.*
,ext.id as external_order_id
,cus.id as external_customer_id
,line_items.*

FROM data,
jsonb_to_record(content) as ord(id int),
LATERAL jsonb_to_record(content->'external_order_id') as ext(id text),
LATERAL jsonb_to_record(content#>'{customer, external_customer_id}') as cus(id text)
CROSS JOIN LATERAL jsonb_to_recordset(content->'line_items') line_items(sku text)

这是迄今为止的结果

| id | external_order_id | external_customer_id | sku   |
|----|-------------------|----------------------|-------|
| 1  | 2                 | 3                    | SKU-1 |
| 1  | 2                 | 3                    | SKU-2 |

我想要实现的是。理想情况下，这将在不知道属性名称的值的情况下实现

| id | external_order_id | external_customer_id | sku   | external_product_id | external_variant_id | property_name | property_value |
|----|-------------------|----------------------|-------|---------------------|---------------------|---------------|----------------|
| 1  | 2                 | 3                    | SKU-1 | 4                   | 5                   | colour        | red            |
| 1  | 2                 | 3                    | SKU-1 | 4                   | 5                   | size          | large          |
| 1  | 2                 | 3                    | SKU-2 | 8                   | 9                   | colour        | black          |
| 1  | 2                 | 3                    | SKU-2 | 8                   | 9                   | size          | small          |

小提琴手

4

1 回答 1

1 
WITH data(content) AS ( VALUES
  ('{
    "id": 1,
         "external_order_id": {
        "id": "2"
    },
    "customer": {

        "external_customer_id": {
            "id": "3"
        }
    },
    "line_items": [
        {
            "sku": "SKU-1",
            "properties": [
                {
                    "name": "colour",
                    "value": "red"
                },
                {
                    "name": "size",
                    "value": "large"
                }
            ],
            "external_product_id": {
                "id": "4"
            },
            "external_variant_id": {
                "id": "5"
            }
        },
                {
            "sku": "SKU-2",
            "properties": [
                {
                    "name": "colour",
                    "value": "black"
                },
                {
                    "name": "size",
                    "value": "small"
                }
            ],
            "external_product_id": {
                "id": "8"
            },
            "external_variant_id": {
                "id": "9"
            }
        }
    ]

}'::jsonb)
)
select ord.*
,ext.id as external_order_id
,cus.id as external_customer_id
,line_items.sku
,line_items.external_product_id->>'id' as external_product_id
,line_items.external_variant_id->>'id' as external_variant_id
,props.*
FROM data,
jsonb_to_record(content) as ord(id int),
LATERAL jsonb_to_record(content->'external_order_id') as ext(id text),
LATERAL jsonb_to_record(content#>'{customer, external_customer_id}') as cus(id text)
CROSS JOIN LATERAL jsonb_to_recordset(content->'line_items') line_items(sku text, properties jsonb, external_product_id jsonb, external_variant_id jsonb)
cross join LATERAL jsonb_to_recordset(line_items.properties) props(name text, value text)
于 2021-12-10T21:06:28.520 回答