JSON queries - Tablestore SDK for Go - Tablestore - Alibaba Cloud Documentation Center

Prerequisites

Before you begin, complete the following preparations:

Install the Tablestore Go SDK and initialize a client.
A search index that contains a JSON field is created. For more information, see Create a search index.

Description

A JSON field supports Object and Nested indexing. Object does not preserve object boundaries within an array, so different objects can satisfy different query conditions. Nested indexes each object in an array as an independent child row and ensures that multiple conditions match within the same array element.

JSON index type	Query method
JsonType_OBJECT	Does not preserve object boundaries in an array. Use the full child-field path in a regular query, such as `profile.city`.
JsonType_NESTED	Preserves field relationships within the same object. Use NestedQuery to query objects in an array.

Note

SubFieldSchemas of a JSON field cannot contain a Vector child field.

Query an Object field

tableName := "example_table"
indexName := "example_index"

query := &search.TermQuery{FieldName: "profile.city", Term: "hangzhou"}
searchQuery := search.NewSearchQuery().
    SetQuery(query).
    SetLimit(10).
    SetGetTotalCount(true)

response, err := client.Search(&tablestore.SearchRequest{
    TableName:   tableName,
    IndexName:   indexName,
    SearchQuery: searchQuery,
    ColumnsToGet: &tablestore.ColumnsToGet{
        ReturnAllFromIndex: true,
    },
})
if err != nil {
    log.Fatal(err)
}

fmt.Println(response.TotalCount)
fmt.Println(response.Rows)

Query a Nested field

tableName := "example_table"
indexName := "example_index"

query := &search.NestedQuery{Path: "orders", Query: &search.TermQuery{FieldName: "orders.product", Term: "book"}, ScoreMode: search.ScoreMode_None}
searchQuery := search.NewSearchQuery().
    SetQuery(query).
    SetLimit(10).
    SetGetTotalCount(true)

response, err := client.Search(&tablestore.SearchRequest{
    TableName:   tableName,
    IndexName:   indexName,
    SearchQuery: searchQuery,
    ColumnsToGet: &tablestore.ColumnsToGet{
        ReturnAllFromIndex: true,
    },
})
if err != nil {
    log.Fatal(err)
}

fmt.Println(response.TotalCount)
fmt.Println(response.Rows)

Parameters

An Object field uses parameters of the selected query type. A Nested field uses search.NestedQuery. For common query configurations, see Term query. For NestedQuery parameters, see Nested query.

Object field query

Name	Type	Description
FieldName (required)	string	The full path of the JSON child field, such as `profile.city`.
Query value (required)	interface{}	The name and type depend on the selected query type.

Nested field query

Name	Type	Description
Path (required)	string	The path of the JsonType_NESTED field.
Query (required)	search.Query	The query condition on child fields.
ScoreMode (optional)	search.ScoreMode	The method used to combine scores from child rows.