: Operator (tanda titik dua)

Berlaku untuk:centang ditandai ya Databricks SQL centang ditandai ya Databricks Runtime

Mengekstrak konten dari string JSON menggunakan ekspresi jalur JSON.

Sintaks

jsonExpr : jsonPath

Argumen

  • jsonExpr: Ekspresi VARIANT atau STRING ekspresi dengan JSON yang valid.
  • jsonPath: Ekspresi jalur JSON.

Mengembalikan

Hasilnya cocok dengan jenis jsonExpr. Jika input bukan JSON yang valid atau ekspresi jalur tidak valid untuk nilai JSON hasilnya adalah NULL. Jika nilai yang diekstraksi adalah tidak dibatasi null hasilnya adalah nilai NULL.

Lihat ekspresi jalur JSON untuk penjelasan terperinci tentang jalur JSON yang valid.

Contoh

> SELECT c1:price
    FROM VALUES('{ "price": 5 }') AS T(c1);
 5

> SELECT c1:['price']::decimal(5,2)
    FROM VALUES('{ "price": 5 }') AS T(c1);
 5.00

> SELECT c1:item[1].price::double
    FROM VALUES('{ "item": [ { "model" : "basic", "price" : 6.12 },
                             { "model" : "medium", "price" : 9.24 } ] }') AS T(c1);
 9.24

> SELECT c1:item[*].price
    FROM VALUES('{ "item": [ { "model" : "basic", "price" : 6.12 },
                             { "model" : "medium", "price" : 9.24 } ] }') AS T(c1);
 [6.12,9.24]

> SELECT from_json(c1:item[*].price, 'ARRAY<DOUBLE>')[0]
      FROM VALUES('{ "item": [ { "model" : "basic", "price" : 6.12 },
                               { "model" : "medium", "price" : 9.24 } ] }') AS T(c1);
 6.12

> SELECT from_json(c1:item[*], 'ARRAY<STRUCT<model STRING, price DOUBLE>>')
      FROM VALUES('{ "item": [ { "model" : "basic", "price" : 6.12 },
                               { "model" : "medium", "price" : 9.24 } ] }') AS T(c1);
  [{"model":"basic","price":6.12},{"model":"medium","price":9.24}]

> SELECT inline(from_json(c1:item[*], 'ARRAY<STRUCT<model STRING, price DOUBLE>>'))
    FROM VALUES('{ "item": [ { "model" : "basic", "price" : 6.12 },
                               { "model" : "medium", "price" : 9.24 } ] }') AS T(c1);
  basic     6.12
  medium    9.24

-- Examples with VARIANT expressions.
> SELECT PARSE_JSON('{ "price": 5 }'):price
 5

> SELECT PARSE_JSON('{ "price": 5 }'):price::decimal(5,2)
 5.00

> SELECT PARSE_JSON('{ "item": [ { "model" : "basic", "price" : 6.12 },
                             { "model" : "medium", "price" : 9.24 } ] }'):item[1].price::double
 9.24
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