Connecting a SingleStore database

type

Required. This argument specifies the type of database to query. Supported values are mysql, postgresql, mssql, snowflake, presto, and SingleStore.

table

Optional. The value of this argument is the name of the database table to be queried. While this value is optional, one of either table or query must be specified.

Using the table argument is the equivalent of writing select * from [table]. The field names of the GraphQL type of the annotated field must match the column names of the underlying database table. Thus, if the table has a NAME column, it will populate the NAME field of the GraphQL type.

If the annotated field has arguments, they are used to construct the WHERE clause of the SQL query. For example, let's look at the following annotated field:

customerById (id: ID!): Customer
  @dbquery (
    type: "singlestore"
    table: "customers"
    configuration: "singlestore_config"
  )

The directive passes the following database query to the database specified by the singlestore_config configuration (See configuration for more information).

SELECT "custkey", "name", "address", "nationkey", "phone", "acctbal", "mktsegment", "comment" FROM "customers" WHERE "custkey" = ?

where, custkey, name, address, nationkey, phone, acctbal, mktsegment, and comment are the columns of the SingleStore table customers that match the fields of the Customer type.

If the annotated field has multiple arguments, they are combined in the SQL WHERE clause with an AND.

query

Optional. The value of this argument is the SQL query whose results are used to populate the sub-fields of the annotated field. While this value is optional, one of either table or query must be specified.

The query argument is useful when you need to perform a complex query, or when the table column names and GraphQL type fields do not match. For example:

customerById (id: ID!): Customer
  @dbquery (
    type: "singlestore",
    query: """"Select "custkey", "full_name" AS "name", "address" FROM "customers" WHERE "custkey" = ? AND "creditCard" IS NOT NULL"""",
    configuration: "singlestore_config"
  )

The directive executes the specified SQL query on the database specified by the singlestore_config. The SQL query both renames full_name to name so it matches the field name in the GraphQL type Customer, and retrieves only those customers who have a credit card.

configuration

Required. This argument identifies which configuration in the config.yaml file should be used to connect to the database.

A SingleStore database configuration contains the dsn for connecting to your database, and will look similar to this:

configurationset:
  - configuration:
      name: singlestore_config
      dsn: "username:password@tcp(hostname)/database?tls=true"

In this example, singlestore_config is the named configuration that will be referenced by the configuration property of @dbquery as configuration: singlestore_config.

To learn more about the configuration settings for connecting to your SingleStore database, see SingleStore configuration.

SingleStoreDB connector capabilities

For explanation about how to use pagination and filtering with the @dbquery directive, see Using @dbquery for pagination and filtering.