Getting started with Looker

Best Practices

Documentation

Community

Training

Certification

Articles in this section

See more

sql_create

Avatar
Looker Support
  • Updated
Follow

Usage

derived_table: customer_order_facts {
  sql_create: {
      SQL statement ;;
  }
}

Hierarchy

view
derived_table
sql_create

Default Value

None

Accepts

A SQL statement

Definition

sql_create enables custom Data Definition Language (DDL) commands for building persistent derived tables (PDTs). sql_create will issue a statement as is, without Looker’s usual error checking. The only requirement is that the statement results in the creation and execution of a PDT. This lets you, for example, create PDTs that support Google’s BigQuery ML (BQML) machine learning models.

create

For PDTs defined using sql_create, you cannot use any of the following parameters:

Examples

Create a PDT for BQML queries that predict likelihood of future purchases:

view: future_purchase_model { derived_table: { datagroup_trigger: bqml_datagroup sql_create: CREATE OR REPLACE MODEL ${SQL_TABLE_NAME} OPTIONS(model_type='logistic_reg' , labels=['will_purchase_in_future'] , min_rel_progress = 0.005 , max_iterations = 40 ) AS SELECT * EXCEPT(fullVisitorId, visitId) FROM ${training_input.SQL_TABLE_NAME};; } }

Things to consider

${SQL_TABLE_NAME} substitution operator

You can use the ${SQL_TABLE_NAME} substitution operator to substitute in the computed name of the PDT being created. This ensures the SQL statement will correctly include the PDT name given in the LookML view parameter.

sql_create must create a table with the name indicated by the ${SQL_TABLE_NAME} substitution operator, or it will be rebuilt from scratch on every trigger check interval specified in a connection’s PDT and Datagroup Maintenance Schedule setting (the default is five minutes). This can cause unexpected query traffic on your database or data warehouse.

Use create_process to create a PDT in multiple steps

If your database dialect requires custom DDL commands, and you want to issue multiple commands to create a PDT, you can use create_process to issue multiple custom DDL commands in a specific order.

Tables defined with sql_create can’t be used for incremental PDTs

To be used as an incremental PDT, a SQL-based PDT must have a query defined using the sql parameter. SQL-based PDTs that are defined with the sql_create parameter or the create_process parameter cannot be incrementally built.

This is because Looker uses an INSERT or a MERGE command to create the increments for an incremental PDT. The derived table cannot be defined using custom Data Definition Language (DDL) statements, since Looker wouldn’t be able to determine which DDL statements would be required to create an accurate increment.