计算golang中的行数 [英] Count number of rows in golang
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问题描述
我想使用Go显示数据库中的行数.如何显示行数?
I want to display the number of rows from database using Go. How do I display number of rows?
count, err := db.Query("SELECT COUNT(*) FROM main_table")
推荐答案
查询将在变量计数中返回一行.因此,下一个要做的就是使用功能Scan()
读取此行并将结果分配到新变量中.这是这样的.
The query will return a row into the variable count. So the next you have to do is to read this row and assign the result into a new variable, using the function Scan()
. This is how it works.
rows, err := db.Query("SELECT COUNT(*) FROM main_table")
if err != nil {
log.Fatal(err)
}
defer rows.Close()
var count int
for rows.Next() {
if err := rows.Scan(&count); err != nil {
log.Fatal(err)
}
}
fmt.Printf("Number of rows are %s\n", count)
最好的选择是使用QueryRow()
,因为您希望只读取一行.这样的代码将是.
The best option thought would be to use QueryRow()
as you expect to read just one row. The code then will be.
var count int
err := db.QueryRow("SELECT COUNT(*) FROM main_table").Scan(&count)
switch {
case err != nil:
log.Fatal(err)
default:
fmt.Printf("Number of rows are %s\n", count)
}
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