Golang is a strongly typed compiled language with the advantages of efficiency, simplicity, and scalability, and has become one of the more popular programming languages at present. In daily programming in Golang, we often encounter situations where data needs to be deleted. So how to write a delete statement in Golang? This article will give you a detailed introduction to how to write Golang's delete statement.
1. Basic concepts
In Golang, the delete operation corresponds to the DELETE statement in the database operation, and its function is to delete the specified data from the data table. Of course, when performing a delete operation, we need to first clarify the following concepts:
- Data table: The delete operation targets the data in the data table, so the data table to be operated must first be determined.
- WHERE clause: This clause is used to specify the data to be deleted. It is usually necessary to provide some search conditions to find the specified data for deletion.
2. Basic syntax of delete statement
In Golang, the basic syntax of delete operation is as follows:
DELETE FROM `table_name` WHERE `condition`;
Among them, DELETE is the keyword, which means to perform deletion Operation; FROM is followed by the name of the data table to be deleted; WHERE is followed by the deletion condition, which is used to specify the data to be deleted.
For example, if we want to delete all user data younger than 20 years old from a data table named users, we can write the following delete statement:
DELETE FROM users WHERE age < 20;
3. Execute the delete statement in Golang
In Golang, to perform a delete operation, you need to use the database/sql standard library and the corresponding database driver. Here we take Sqlite database as an example to introduce how to perform a delete operation.
- Import necessary libraries
Before writing the Golang delete statement, you need to import some necessary libraries, as shown below:
import ( "database/sql" "fmt" _ "github.com/mattn/go-sqlite3" )
Among them, # The ##database/sql package is the standard library for relational database operations in Golang, and
github.com/mattn/go-sqlite3 is the driver library for connecting to Sqlite databases.
- Connect to the database
db, err := sql.Open("sqlite3", "./test.db") if err != nil { fmt.Println(err) return } defer db.Close()Here, a Sqlite database named test.db will be opened, and the connection information is stored in the db variable. Use the
defer statement to close the connection to ensure that the database connection can be closed normally when the program execution ends.
- Writing a delete statement
sqlStr := "DELETE FROM users WHERE age < ?"Among them,
users is the name of the data table to be deleted,
age means to delete data whose age is less than the provided parameter value.
- Perform deletion operation
stmt, err := db.Prepare(sqlStr) if err != nil { fmt.Println(err) return } defer stmt.Close() result, err := stmt.Exec(20) if err != nil { fmt.Println(err) return } rowsAffected, err := result.RowsAffected() if err != nil { fmt.Println(err) return } fmt.Printf("删除了%d条数据 ", rowsAffected)In the above code, use
db.Prepare()Function compiles SQL statements and creates an stmt object. Use the
Exec method of the stmt object to execute the SQL statement, passing the parameters to the placeholders in the SQL WHERE clause. In addition, use the
result.RowsAffected() method to get the number of rows affected by deletion and output it.
The above is the detailed content of golang delete statement. For more information, please follow other related articles on the PHP Chinese website!

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