Tablestore:Query index information about tables

Prerequisites

• An OTSClient instance is initialized. For more information, see Initialize an OTSClient instance.

• A mapping table is created. For more information, see Create mapping tables for tables.

Parameters

Examples

The following sample code provides an example on how to run the show index in test_table statement to query the index information about the table named test_table:

func showIndex(client *tablestore.TableStoreClient) {
    // Create an SQL request. 
    request := &tablestore.SQLQueryRequest{Query: "show index in test_table"}

    // Obtain the response to the SQL request. 
    response, err := client.SQLQuery(request)
    if err != nil {
        panic(err)
    }

    // Obtain the schema of the returned results of the SQL request. 
    columns := response.ResultSet.Columns()
    fmt.Printf("response table schema:[")
    for l := 0; l < len(columns); l++ {
        fmt.Printf("%v:%v ", columns[l].Name, columns[l].Type.String())
    }

    // Use SQL ResultSet to obtain all returned results of the SQL request. 
    fmt.Println("]\nresponse resultset:")
    resultSet := response.ResultSet
    for resultSet.HasNext() {
        row := resultSet.Next()
        tableName, _ := row.GetStringByName("Table")
        fmt.Printf("%v, ", tableName)
        nonUnique, _ := row.GetInt64ByName("Non_unique")
        fmt.Printf("%v, ", nonUnique)
        keyName, _ := row.GetStringByName("Key_name")
        fmt.Printf("%v, ", keyName)
        seqInIndex, _ := row.GetInt64ByName("Seq_in_index")
        fmt.Printf("%v, ", seqInIndex)
        columnName, _ := row.GetStringByName("Column_name")
        fmt.Printf("%v, ", columnName)
        indexType, _ := row.GetStringByName("Index_type")
        fmt.Printf("%v\n", indexType)
    }
}

Sample response:

response table schema: [Table:STRING Non_unique:INTEGER Key_name:STRING Seq_in_index:INTEGER Column_name:STRING Is_defined_column:STRING Search_type:STRING Collation:STRING Cardinality:INTEGER Sub_part:INTEGER Packed:STRING Null:STRING Index_type:STRING Comment:STRING Index_comment:STRING Visible:STRING Expression:STRING]
response resultset:
test_table, 0, PRIMARY, 1, pk,
test_table, 1, test_table_index, 1, pk, SearchIndex
test_table, 1, test_table_index, 2, bool_value, SearchIndex
test_table, 1, test_table_index, 3, double_value, SearchIndex
test_table, 1, test_table_index, 4, long_value, SearchIndex
test_table, 1, test_table_index, 5, string_value, SearchIndex

References

• If you want to use a specific search index to query data when you use the SQL query feature, you can execute the CREATE TABLE statement to create a mapping table for the search index. For more information, see Create mapping tables for search indexes.

• You can execute SQL statements to query data based on the fields of an index. For more information, see Query data.