Linting queries

Added in v1.19.0

sqlc vet runs queries through a set of lint rules.

Rules are defined in the sqlc configuration file. They consist of a name, message, and a Common Expression Language (CEL) expression. Expressions are evaluated using cel-go. If an expression evaluates to true, an error is reported using the given message.

Each expression has access to variables from your sqlc configuration and queries, defined in the following struct:

message Config
{
  string version = 1;
  string engine = 2 ;
  repeated string schema = 3;
  repeated string queries = 4;
}

message Query
{
  // SQL body
  string sql = 1;
  // Name of the query
  string name = 2; 
  // One of :many, :one, :exec, etc.
  string cmd = 3;
  // Query parameters, if any
  repeated Parameter params = 4;
}

message Parameter
{
  int32 number = 1;
}

This struct will likely expand in the future to include more query information. We may also add information returned from a running database, such as the result from EXPLAIN ....

While these examples are simplistic, they give you a flavor of the types of rules you can write.

version: 2
sql:
  - schema: "query.sql"
    queries: "query.sql"
    engine: "postgresql"
    gen:
      go:
        package: "authors"
        out: "db"
    rules:
      - no-pg
      - no-delete
      - only-one-param
      - no-exec
rules:
  - name: no-pg
    message: "invalid engine: postgresql"
    rule: |
      config.engine == "postgresql"
  - name: no-delete
    message: "don't use delete statements"
    rule: |
      query.sql.contains("DELETE")
  - name: only-one-param
    message: "too many parameters"
    rule: |
      query.params.size() > 1
  - name: no-exec
    message: "don't use exec"
    rule: |
      query.cmd == "exec"

Built-in rules

sqlc/db-prepare

When a database connection is configured, you can run the built-in sqlc/db-preapre rule. This rule will attempt to prepare each of your queries against the connected database and report any failures.

version: 2
sql:
  - schema: "query.sql"
    queries: "query.sql"
    engine: "postgresql"
    gen:
      go:
        package: "authors"
        out: "db"
    database:
      uri: "postgresql://postgres:password@localhost:5432/postgres"
    rules:
      - sqlc/db-prepare

To see this in action, check out the authors example.

Please note that sqlc does not manage or migrate your database. Use your migration tool of choice to create the necessary database tables and objects before running sqlc vet.