Go语言go-sqlite3库：正确使用SELECT查询获取数据

    CheckTable, err := db.Prepare("SELECT name FROM sqlite_master WHERE type='table' AND name='testtable';")
    // ... 错误处理 ...
    err = CheckTable.Exec() // <--- 错误的使用方式
    // ... 错误处理 ...
    var tablename string
    err = CheckTable.Scan(&tablename) // <--- 试图扫描一个不存在的结果集
    // ... 错误处理 ...

package main

import (
    "fmt"
    "os"
    "time"

    "code.google.com/p/go-sqlite/go1/sqlite3"
)

func main() {
    dbname := "sqlite.db"
    // 延迟5秒，以便观察程序输出，实际应用中可能不需要
    defer time.Sleep(5000 * time.Millisecond)

    fmt.Printf("hello, world\n")

    // 确保每次运行时数据库文件是新的，便于测试
    os.Remove(dbname)

    fe := FileExists(dbname)
    fmt.Printf("FileExists(dbname) returned: %t\n", fe)

    db, err := sqlite3.Open(dbname)
    if err != nil {
        fmt.Printf("failed to open database, error: " + err.Error() + "\n")
        return
    }
    defer db.Close() // 确保数据库连接在函数结束时关闭

    fmt.Printf("database ok\n")

    if !fe { // 如果文件不存在，则创建表并插入数据
        fmt.Printf("creating testtable...\n")
        err = db.Exec("CREATE TABLE testtable (id INTEGER PRIMARY KEY AUTOINCREMENT, text VARCHAR(200));")
        if err != nil {
            fmt.Printf("error creating table: " + err.Error() + "\n")
            return
        }
        fmt.Printf("success!\n")

        fmt.Printf("inserting something...\n")
        insertSql := `INSERT INTO testtable(text) VALUES("This is some random text to test it");`
        err = db.Exec(insertSql)
        if err != nil {
            fmt.Printf("Error while Inserting: " + err.Error() + "\n")
            return
        }
    }

    fmt.Printf("checking testtable...\n")

    // 准备查询语句
    stmt, err := db.Prepare("SELECT name FROM sqlite_master WHERE type='table' AND name='testtable';")
    if err != nil {
        fmt.Printf("failed to prepare statement, error: " + err.Error() + "\n")
        return
    }
    defer stmt.Close() // 确保预处理语句在函数结束时关闭

    // 使用 Query() 执行 SELECT 语句，并获取结果集
    rows, err := stmt.Query()
    if err != nil {
        fmt.Printf("failed to query table, error: " + err.Error() + "\n")
        return
    }
    defer rows.Close() // 确保结果集在函数结束时关闭

    var tableDetected bool
    // 遍历结果集
    for rows.Next() {
        var tablename string
        // 扫描当前行的列数据
        if err := rows.Scan(&tablename); err != nil {
            fmt.Printf("Failed to scan variable, error: " + err.Error() + "\n")
            return
        }
        if tablename == "testtable" {
            tableDetected = true
            break // 找到表了，可以提前退出循环
        }
    }

    // 检查遍历过程中是否发生错误
    if err := rows.Err(); err != nil {
        fmt.Printf("Error during rows iteration: " + err.Error() + "\n")
        return
    }

    if tableDetected {
        fmt.Printf("Table detected\n")
    } else {
        fmt.Printf("No table detected\n")
    }
}

// FileExists 检查文件是否存在
func FileExists(fn string) bool {
    if _, err := os.Stat(fn); err == nil {
        return true
    }
    return false
}

hello, world
FileExists(dbname) returned: false
database ok
creating testtable...
success!
inserting something...
checking testtable...
Table detected