You can execute the CREATE TABLE statement to create a mapping table for an existing table or search index. When you create a mapping table, specify the field names and types, primary key information, and the execution engine you want to use for data queries based on your business requirements.
For more information, see Create a mapping table for a table and Create mapping tables for search indexes.
Prerequisites
A client is initialized. For more information, see Initialize a Tablestore client.
If you want to create a mapping table for a search index, you must first create the search index.
Parameters
Parameter | Description |
query | The SQL statement. Configure this parameter based on the required feature. |
Examples
This topic describes how to create a mapping table for a table. If you want to create a mapping table for a search index, replace the SQL statement in the sample code with the SQL statement used to create a mapping table for a search index.
The following example shows how to create a mapping table for the test_table table by using the statement create table test_table (pk varchar(1024), long_value bigint, double_value double, string_value mediumtext, bool_value bool, primary key(pk)).
const params = {
query: "create table test_table (pk varchar(1024), long_value bigint, double_value double, string_value mediumtext, bool_value bool, primary key(pk))",
}
client.sqlQuery(params, function (err, data) {
if (err) {
console.log('sqlQuery error:', err.toString());
} else {
console.log('sqlQuery success:', data);
}
});FAQ
What do I do if the "Table 'instancename.tablename' doesn't exist ?" error message is returned when I create a mapping table?
Possible cause
The table for which you want to create a mapping table does not exist.
Solution
You can execute the CREATE TABLE statement in SQL to create a mapping table only for an existing table or search index. Make sure that the table or search index for which you want to create a mapping table exists.
What do I do if the "Table 'instancename.tablename' already exist?" error message is returned when I create a mapping table?
Possible cause
A mapping table is created for the table.
The user manually created a mapping table for the table.
Tablestore automatically created a mapping table for the table. If you directly use SQL statements (such as DESCRIBE, SELECT, etc.) to query data in a data table without creating a mapping table for the data table, Tablestore automatically creates a mapping table for the data table. The automatically created mapping table only contains the primary key columns and predefined columns of the data table. You cannot update the attribute columns of the mapping table.
Solution
You can execute the
DESCRIBEstatement to query the schema of the mapping table. If the schema does not meet your business requirements, you can update the attribute columns of the mapping table. If the mapping table is automatically created by Tablestore, you cannot update the attribute columns. In this case, you can delete the mapping table and create a new one if you are sure that your business is not affected after you delete the mapping table.
For common errors and solutions of the SQL query feature, see How do I troubleshoot common errors of SQL queries?.
References
After you create a mapping table, you can update the attribute columns of the mapping table, query information of the mapping table, query the names of mapping tables, query the index information of the mapping table, and delete the mapping table. For more information, see Update attribute columns of a mapping table, Query information about a table, List the names of tables, Query index information about tables, or Delete a mapping table.
You can execute the SELECT statement to query and analyze data in a mapping table. For more information, see Query data.