Adding named foreign key constraints in a SQL Create statement

Rumpleteaser picture Rumpleteaser · Jan 24, 2013 · Viewed 38k times · Source

I currently have:

CREATE TABLE  galleries_gallery (
    id              INT NOT NULL PRIMARY KEY IDENTITY,
    title           NVARCHAR(50) UNIQUE NOT NULL,
    description     VARCHAR(256),
    templateID      INT NOT NULL REFERENCES galleries_templates(id),
    jsAltImgID      INT NOT NULL REFERENCES libraryImage(id)
    jsAltText       NVARCHAR(500),
    dateCreated     SMALLDATETIME NOT NULL,
    dateUpdated     SMALLDATETIME NOT NULL,
    lastUpdatedBy   INT,
    deleted         BIT NOT NULL DEFAULT 0
);

But this adds constraints with auto generated names which make it hard to drop the constraint later. What do I need to add in order to name the constraints?

The above example is SQL Server and I also need it in PostgreSQL.

Answer

Cristian Lupascu picture Cristian Lupascu · Jan 24, 2013

In SQL Server, you can use the constraint keyword to define foreign keys inline and name them at the same time.

Here's the updated script:

CREATE TABLE  galleries_gallery (
    id              INT NOT NULL PRIMARY KEY IDENTITY,
    title           NVARCHAR(50) UNIQUE NOT NULL,
    description     VARCHAR(256),
    templateID      INT NOT NULL 
        CONSTRAINT FK_galerry_template 
        REFERENCES galleries_templates(id),
    jsAltImgID      INT NOT NULL 
        CONSTRAINT FK_gallery_jsAltImg
        REFERENCES libraryImage(id)
    jsAltText       NVARCHAR(500),
    dateCreated     SMALLDATETIME NOT NULL,
    dateUpdated     SMALLDATETIME NOT NULL,
    lastUpdatedBy   INT,
    deleted         BIT NOT NULL DEFAULT 0
);

I just made a test and apparently the same thing also works in PostgreSQL: http://www.sqlfiddle.com/#!12/2ae29