CODEWITHSUNDEEP
mysqlsqliteindexing
Niek de Klein
Niek de Klein

Reputation: 8824

How to correctly do CREATE INDEX with SQLite

I'm trying to convert my MySQL create table statements to SQLite create table statements. Most of it I've done, however I don't know how to change MySQL's UNIQUE INDEX to Sqlites CREATE INDEX (I thought that these were roughly the same, please correct me if I'm wrong).

So I have the following MySQL table (it's changed a bit from the :

-- -----------------------------------------------------
-- Table `pyMS`.`feature`
-- -----------------------------------------------------
CREATE  TABLE IF NOT EXISTS `pyMS`.`feature` (
  `feature_id` VARCHAR(40) NOT NULL ,
  `intensity` DOUBLE NOT NULL ,
  `overallquality` DOUBLE NOT NULL ,
  `quality` DOUBLE NOT NULL ,
  `charge` INT NOT NULL ,
  `content` VARCHAR(45) NOT NULL ,
  `msrun_msrun_id` INT NOT NULL ,
  PRIMARY KEY (`feature_id`, `msrun_msrun_id`) ,
  UNIQUE INDEX `id_UNIQUE` (`feature_id` ASC) ,
  INDEX `fk_feature_msrun1` (`msrun_msrun_id` ASC) ,
  CONSTRAINT `fk_feature_msrun1`
    FOREIGN KEY (`msrun_msrun_id` )
    REFERENCES `pyMS`.`msrun` (`msrun_id` )
    ON DELETE NO ACTION
    ON UPDATE NO ACTION)
ENGINE = InnoDB;

And I changed the index according to http://www.sqlite.org/lang_createindex.html. I did also change some other things to go from MySQL to SQLite but I tested it and they work. So this is my SQLite code:

-- -----------------------------------------------------
-- Table `feature`
-- -----------------------------------------------------
CREATE  TABLE IF NOT EXISTS `feature` (
  `feature_id` VARCHAR(40) NOT NULL ,
  `intensity` DOUBLE NOT NULL ,
  `overallquality` DOUBLE NOT NULL ,
  `quality` DOUBLE NOT NULL ,
  `charge` INT NOT NULL ,
  `content` VARCHAR(45) NOT NULL ,
  `msrun_msrun_id` INT NOT NULL ,
  CREATE UNIQUE INDEX `id_UNIQUE` ON `feature` (`feature_id` ASC) ,
  CREATE INDEX `fk_feature_msrun1` ON `msrun` (`msrun_msrun_id` ASC) ,
  CONSTRAINT `fk_feature_msrun1`
    FOREIGN KEY (`msrun_msrun_id` )
    REFERENCES `msrun` (`msrun_id` )
    ON DELETE NO ACTION
    ON UPDATE NO ACTION);

This does not work. When I remove the INDEX lines it does work. As far as I can see the INDEX lines comply to this description http://www.sqlite.org/lang_createindex.html, I don't see where it goes wrong. So how can I change the two lines 

CREATE UNIQUE INDEX `id_UNIQUE` ON `feature` (`feature_id` ASC) ,
CREATE INDEX `fk_feature_msrun1` ON `msrun` (`msrun_msrun_id` ASC) ,

to make their syntax correct?

Upvotes: 30

Views: 48819

Answers (2)

Mike Sherrill 'Cat Recall'
Mike Sherrill 'Cat Recall'

Reputation: 95532

You need to look at CREATE TABLE syntax, not CREATE INDEX. SQLite will accept this form of a UNIQUE constraint in a CREATE TABLE statement.

CREATE  TABLE IF NOT EXISTS `feature` (
...
  CONSTRAINT `id_UNIQUE` UNIQUE (`feature_id`),
...
);

Upvotes: 17

Justin ᚅᚔᚈᚄᚒᚔ
Justin ᚅᚔᚈᚄᚒᚔ

Reputation: 15369

CREATE UNIQUE INDEX is its own statement and cannot be used within a CREATE TABLE statement.

Move the index statements out of CREATE TABLE:

CREATE  TABLE IF NOT EXISTS `feature` (
  `feature_id` VARCHAR(40) NOT NULL ,
  `intensity` DOUBLE NOT NULL ,
  `overallquality` DOUBLE NOT NULL ,
  `quality` DOUBLE NOT NULL ,
  `charge` INT NOT NULL ,
  `content` VARCHAR(45) NOT NULL ,
  `msrun_msrun_id` INT NOT NULL,
  CONSTRAINT `fk_feature_msrun1`
    FOREIGN KEY (`msrun_msrun_id` )
    REFERENCES `msrun` (`msrun_id` )
    ON DELETE NO ACTION
    ON UPDATE NO ACTION);
CREATE UNIQUE INDEX `id_UNIQUE` ON `feature` (`feature_id` ASC);
CREATE INDEX `fk_feature_msrun1` ON `feature` (`msrun_msrun_id` ASC);

Upvotes: 50

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