Unify your SQL schema and your GraphQL Schema. Use GraphQL SDL as the lingua franca to define your data requirements.

Given a GraphQL schema defined in SDL, this function will output a schema script which, when ran on your database, will create all the tables in your database.

node generate-sql.js

// generate-sql.js
const gql = require('graphql-tag')
const {
  makeSqlSchema,
  getSchemaDirectives
} = require('graphql-to-sql')

const typeDefs = gql`
  directive @sql (
    unicode: Boolean
    constraints: String
    auto: Boolean
    default: String
    index: Boolean
    nullable: Boolean
    primary: Boolean
    type: String
    unique: Boolean
  ) on OBJECT | FIELD_DEFINITION

  # See graphql-directive-private
  directive @private on OBJECT | FIELD_DEFINITION

  type User @sql(unicode: true) {
    userId: String @sql(type: "BINARY(16)", primary: true)
    uniqueColumn: Int @sql(unique: true)
    databaseOnlyField: Int @sql @private
    
    graphqlOnlyField: String
    posts: [Post]
  }

  type Post {
    postId: Int @sql(primary: true, auto: true)
    userId: String @sql(type: "BINARY(16)", index: true)
    content: String @sql(type: "VARCHAR(300)", unicode: true, nullable: true)
    likes: Int @sql
    dateCreated: String @sql(type: "TIMESTAMP", default: "CURRENT_TIMESTAMP")
  }
  
  type UserPair @sql(constraints: "UNIQUE(parentUserId, childUserId),\\n  FOREIGN KEY (parentUserId) REFERENCES User(userId)") {
    userPairId: String @sql(type: "BINARY(16)", primary: true)
    parentUserId: String @sql(type: "BINARY(16)", index: true)
    childUserId: String @sql(type: "BINARY(16)", index: true)
  }
`

const outputFilepath = 'schemaScript.sql'
const directives = getSchemaDirectives()
makeSqlSchema({
  typeDefs,
  schemaDirectives: directives,
  outputFilepath,
  databaseName: 'dbname',
  tablePrefix: 'test_',
})

The script above will produce this file:

-- schemaScript.sql
CREATE TABLE `dbname`.`test_User` (
  `userId` BINARY(16) NOT NULL,
  `uniqueColumn` INT NOT NULL UNIQUE,
  `databaseOnlyField` INT NOT NULL,
  PRIMARY KEY (`userId`)
) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

CREATE TABLE `dbname`.`test_Post` (
  `postId` INT NOT NULL AUTO_INCREMENT,
  `userId` BINARY(16) NOT NULL,
  `content` VARCHAR(300) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NULL,
  `likes` INT NOT NULL,
  `dateCreated` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`postId`),
  INDEX `USERIDINDEX` (`userId` ASC)
) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

CREATE TABLE `dbname`.`test_UserPair` (
  `userPairId` BINARY(16) NOT NULL,
  `parentUserId` BINARY(16) NOT NULL,
  `childUserId` BINARY(16) NOT NULL,
  PRIMARY KEY (`userPairId`),
  INDEX `PARENTUSERIDINDEX` (`parentUserId` ASC),
  INDEX `CHILDUSERIDINDEX` (`childUserId` ASC),
  UNIQUE(parentUserId, childUserId),
  FOREIGN KEY (parentUserId) REFERENCES User(userId)
);

Also see main-test.ts for a working example.

For reference:

CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name
    (create_definition,...)
    [table_options]
    [partition_options]

ON OBJECT:

• unicode
  • Adds CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci as table_option.
• constraints
  • Any text written in here will be appended "as is" to the create_definition.

ON FIELD_DEFINITION:

• auto
  • Marks a column as being AUTO_INCREMENT.
  • Column with "auto" must have INT or SERIAL type.
  • "default" is not allowed with "auto".
  • "unicode" is not allowed with "auto".
• default
  • Sets the DEFAULT clause.
• index
  • Creates an index for the column.
• nullable
  • Marks the column with NULL. By default, all columns are NOT NULL.
• primary
  • Creates a PRIMARY KEY clause for the column.
  • At least one column needs to be marked as "primary".
  • "primary" is not allowed with "nullable".
• type
  • Specify the column type.
  • If type is not specified, the MySQL type will be inferred from the GraphQL type.
  • GraphQLString types must be explicitly defined using "type".
• unicode
  • If any column is marked with "unicode", then the table will have CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci.
• unique
  • Marks a column with the UNIQUE keyword.
• generated
  • Marks a generated column.
  • Example: @sql(generated: "(data->>'$.test')"). See main-test.ts for more examples.

• Auto Increment
• Default
• Index
• Not Null
• Primary Key
• Unicode
• Unique
• Check
• Constraints
• Foreign Key (via @constraints)
• Generated Columns

¹Only MySQL is supported at the moment.