Offset specify the number of records to skip before starting to return the records db.Limit( 3).Find(&users)ĭb.Limit( 10).Find(&users1).Limit( -1). Limit specify the max number of records to retrieve SELECT * FROM users ORDER BY FIELD(id,1,2,3) When the destination object has a primary value, the primary key will be used to build the condition, for example: var user = User, If the primary key is a string (for example, like a uuid), the query will be written as follows: db.First(&user, "id = ?", "1b74413f-f3b8-409f-ac47-e8c062e3472a") SELECT * FROM users WHERE id IN (1,2,3) When working with strings, extra care needs to be taken to avoid SQL Injection check out Security section for details. The following statement joins two tables: one is only used to satisfy a WHERE condition, but no row is deleted from it rows from the other table are deleted. Objects can be retrieved using primary key by using Inline Conditions if the primary key is a number. SELECT * FROM `languages` ORDER BY `languages`.`code` LIMIT 1 no primary key defined, results will be ordered by first field (i.e., `Code`) works because model is specified using `db.Model()` SELECT * FROM `users` ORDER BY `users`.`id` LIMIT 1 works because destination struct is passed in Additionally, if no primary key is defined for relevant model, then the model will be ordered by the first field. The schema (I use SQL Server) Table EfTable1. They only work when a pointer to the destination struct is passed to the methods as argument or when the model is specified using db.Model(). I have a problem when I want to join the same table twice (once with object property and once with collection property) (the code is attached, with SQL script), EF generate an INNER JOIN for the object property instead of a LEFT JOIN. The First and Last methods will find the first and last record (respectively) as ordered by primary key. Using Find without a limit for single object db.Find(&user) will query the full table and return only the first object which is not performant and nondeterministic If you want to avoid the ErrRecordNotFound error, you could use Find like db.Limit(1).Find(&user), the Find method accepts both struct and slice data Result.RowsAffected // returns count of records foundĮrrors.Is(result.Error, gorm.ErrRecordNotFound) SELECT * FROM users ORDER BY id DESC LIMIT 1 Get last record, ordered by primary key desc SELECT * FROM users ORDER BY id LIMIT 1 Get the first record ordered by primary key GORM provides First, Take, Last methods to retrieve a single object from the database, it adds LIMIT 1 condition when querying the database, and it will return the error ErrRecordNotFound if no record is found.
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