1. package main
  2.  
  3. import (
  4.     "database/sql"
  5.     "fmt"
  6.  
  7.     _ "github.com/go-sql-driver/mysql"
  8. )
  9.  
  10. var DB *sql.DB
  11.  
  12. func initDb() error {
  13.     var err error
  14.     dsn := "root:root@tcp(localhost:3306)/golang_db"
  15.     DB, err = sql.Open("mysql", dsn)
  16.     if err != nil {
  17.         return err
  18.     }
  19.  
  20.     DB.SetMaxOpenConns()
  21.     DB.SetMaxIdleConns()
  22.     return nil
  23. }
  24.  
  25. type User struct {
  26.     Id   int64          `db:"id"`
  27.     Name sql.NullString `db:"string"`
  28.     Age  int            `db:"age"`
  29. }
  30.  
  31. func testQueryMultilRow() {
  32.     sqlstr := "select id, name, age from user where id > ?"
  33.     rows, err := DB.Query(sqlstr, )
  34.     //重点关注， rows对象一定要close掉
  35.     defer func() {
  36.         if rows != nil {
  37.             rows.Close()
  38.         }
  39.     }()
  40.  
  41.     if err != nil {
  42.         fmt.Printf("query failed, err:%v\n", err)
  43.         return
  44.     }
  45.  
  46.     for rows.Next() {
  47.         var user User
  48.         err := rows.Scan(&user.Id, &user.Name, &user.Age)
  49.         if err != nil {
  50.             fmt.Printf("scan failed, err:%v\n", err)
  51.             return
  52.         }
  53.         fmt.Printf("user:%#v\n", user)
  54.     }
  55.  
  56. }
  57.  
  58. func testQueryData() {
  59.     for i := ; i < ; i++ {
  60.         fmt.Printf("query %d times\n", i)
  61.         sqlstr := "select id, name, age from user where id=?"
  62.         row := DB.QueryRow(sqlstr, )
  63.         /*if row != nil {
  64.             continue
  65.         }*/
  66.         var user User
  67.         err := row.Scan(&user.Id, &user.Name, &user.Age)
  68.         if err != nil {
  69.             fmt.Printf("scan failed, err:%v\n", err)
  70.             return
  71.         }
  72.  
  73.         fmt.Printf("id:%d name:%v age:%d\n", user.Id, user.Name, user.Age)
  74.     }
  75.  
  76. }
  77.  
  78. func testInsertData() {
  79.     sqlstr := "insert into user(name, age) values(?, ?)"
  80.     result, err := DB.Exec(sqlstr, "tom", )
  81.     if err != nil {
  82.         fmt.Printf("insert failed, err:%v\n", err)
  83.         return
  84.     }
  85.  
  86.     id, err := result.LastInsertId()
  87.     if err != nil {
  88.         fmt.Printf("get last insert id failed, err:%v\n", err)
  89.         return
  90.     }
  91.     fmt.Printf("id is %d\n", id)
  92. }
  93.  
  94. func testUpdateData() {
  95.     sqlstr := "update user set name=? where id=?"
  96.     result, err := DB.Exec(sqlstr, "jim", )
  97.     if err != nil {
  98.         fmt.Printf("insert failed, err:%v\n", err)
  99.         return
  100.     }
  101.  
  102.     affected, err := result.RowsAffected()
  103.     if err != nil {
  104.         fmt.Printf("get affected rows failed, err:%v\n", err)
  105.     }
  106.     fmt.Printf("update db succ, affected rows:%d\n", affected)
  107. }
  108.  
  109. func testDeleteData() {
  110.     sqlstr := "delete from user where id=?"
  111.     result, err := DB.Exec(sqlstr, )
  112.     if err != nil {
  113.         fmt.Printf("insert failed, err:%v\n", err)
  114.         return
  115.     }
  116.  
  117.     affected, err := result.RowsAffected()
  118.     if err != nil {
  119.         fmt.Printf("get affected rows failed, err:%v\n", err)
  120.     }
  121.     fmt.Printf("delete db succ, affected rows:%d\n", affected)
  122. }
  123.  
  124. func testPrepareData() {
  125.     sqlstr := "select id, name, age from user where id > ?"
  126.     stmt, err := DB.Prepare(sqlstr)
  127.     if err != nil {
  128.         fmt.Printf("prepare failed, err:%v\n", err)
  129.         return
  130.     }
  131.  
  132.     defer func() {
  133.         if stmt != nil {
  134.             stmt.Close()
  135.         }
  136.     }()
  137.  
  138.     rows, err := stmt.Query()
  139.     //重点关注， rows对象一定要close掉
  140.     defer func() {
  141.         if rows != nil {
  142.             rows.Close()
  143.         }
  144.     }()
  145.  
  146.     if err != nil {
  147.         fmt.Printf("query failed, err:%v\n", err)
  148.         return
  149.     }
  150.  
  151.     for rows.Next() {
  152.         var user User
  153.         err := rows.Scan(&user.Id, &user.Name, &user.Age)
  154.         if err != nil {
  155.             fmt.Printf("scan failed, err:%v\n", err)
  156.             return
  157.         }
  158.         fmt.Printf("user:%#v\n", user)
  159.     }
  160. }
  161.  
  162. func testPrepareInsertData() {
  163.     sqlstr := "insert into user(name, age) values(?, ?)"
  164.     stmt, err := DB.Prepare(sqlstr)
  165.     if err != nil {
  166.         fmt.Printf("insert failed, err:%v\n", err)
  167.         return
  168.     }
  169.  
  170.     defer func() {
  171.         if stmt != nil {
  172.             stmt.Close()
  173.         }
  174.     }()
  175.     result, err := stmt.Exec("jim", )
  176.     id, err := result.LastInsertId()
  177.     if err != nil {
  178.         fmt.Printf("get last insert id failed, err:%v\n", err)
  179.         return
  180.     }
  181.     fmt.Printf("id is %d\n", id)
  182. }
  183.  
  184. func testTrans() {
  185.  
  186.     conn, err := DB.Begin()
  187.     if err != nil {
  188.         if conn != nil {
  189.             conn.Rollback()
  190.         }
  191.         fmt.Printf("begin failed, err:%v\n", err)
  192.         return
  193.     }
  194.  
  195.     sqlstr := "update user set age = 1 where id = ?"
  196.     _, err = conn.Exec(sqlstr, )
  197.     if err != nil {
  198.         conn.Rollback()
  199.         fmt.Printf("exec sql:%s failed, err:%v\n", sqlstr, err)
  200.         return
  201.     }
  202.  
  203.     sqlstr = "update user set age = 2 where id = ?"
  204.     _, err = conn.Exec(sqlstr, )
  205.     if err != nil {
  206.         conn.Rollback()
  207.         fmt.Printf("exec second sql:%s failed, err:%v\n", sqlstr, err)
  208.         return
  209.     }
  210.     err = conn.Commit()
  211.     if err != nil {
  212.         fmt.Printf("commit failed, err:%v\n", err)
  213.         conn.Rollback()
  214.         return
  215.     }
  216. }
  217.  
  218. func main() {
  219.     err := initDb()
  220.     if err != nil {
  221.         fmt.Printf("init db failed, err:%v\n", err)
  222.         return
  223.     }
  224.  
  225.     //testQueryData()
  226.     //testQueryMultilRow()
  227.     //testInsertData()
  228.     //testUpdateData()
  229.     //testDeleteData()
  230.     //testPrepareData()
  231.     //testPrepareInsertData()
  232.     testTrans()
  233. }
  1. package main
  2.  
  3. import (
  4.     "database/sql"
  5.     "fmt"
  6.  
  7.     _ "github.com/go-sql-driver/mysql"
  8.     "github.com/jmoiron/sqlx"
  9. )
  10.  
  11. var DB *sqlx.DB
  12.  
  13. func initDb() error {
  14.     var err error
  15.     dsn := "root:root@tcp(localhost:3306)/golang_db"
  16.     DB, err = sqlx.Open("mysql", dsn)
  17.     if err != nil {
  18.         return err
  19.     }
  20.  
  21.     DB.SetMaxOpenConns()
  22.     DB.SetMaxIdleConns()
  23.     return nil
  24. }
  25.  
  26. type User struct {
  27.     Id   int64          `db:"id"`
  28.     Name sql.NullString `db:"name"`
  29.     Age  int            `db:"age"`
  30. }
  31.  
  32. func testQuery() {
  33.     sqlstr := "select id, name, age from user where id=?"
  34.     var user User
  35.  
  36.     err := DB.Get(&user, sqlstr, )
  37.     if err != nil {
  38.         fmt.Printf("get failed, err:%v\n", err)
  39.         return
  40.     }
  41.  
  42.     fmt.Printf("user:%#v\n", user)
  43. }
  44.  
  45. func testQueryMulti() {
  46.     sqlstr := "select id, name, age from user where id>?"
  47.     var user []User
  48.  
  49.     err := DB.Select(&user, sqlstr, )
  50.     if err != nil {
  51.         fmt.Printf("get failed, err:%v\n", err)
  52.         return
  53.     }
  54.  
  55.     fmt.Printf("user:%#v\n", user)
  56. }
  57.  
  58. func testUpdate() {
  59.     sqlstr := "update user set name=? where id=?"
  60.     result, err := DB.Exec(sqlstr, "abc", )
  61.     if err != nil {
  62.         fmt.Printf("update failed, err:%v\n", err)
  63.         return
  64.     }
  65.     count, err := result.RowsAffected()
  66.     if err != nil {
  67.         fmt.Printf("affected rows failed, err:%v\n", err)
  68.         return
  69.     }
  70.     fmt.Printf("affect rows:%d\n", count)
  71. }
  72.  
  73. func queryDB(name string) {
  74.     sqlstr := fmt.Sprintf("select id, name, age from user where name='%s'", name)
  75.     fmt.Printf("sql:%s\n", sqlstr)
  76.     var user []User
  77.     err := DB.Select(&user, sqlstr)
  78.     if err != nil {
  79.         fmt.Printf("select failed, err:%v\n", err)
  80.         return
  81.     }
  82.  
  83.     for _, v := range user {
  84.         fmt.Printf("user:%#v\n", v)
  85.     }
  86. }
  87.  
  88. func queryDBBySqlx(name string) {
  89.     sqlstr := "select id, name, age from user where name=?"
  90.     //fmt.Printf("sql:%s\n", sqlstr)
  91.     var user []User
  92.     err := DB.Select(&user, sqlstr, name)
  93.     if err != nil {
  94.         fmt.Printf("select failed, err:%v\n", err)
  95.         return
  96.     }
  97.  
  98.     for _, v := range user {
  99.         fmt.Printf("user:%#v\n", v)
  100.     }
  101. }
  102.  
  103. func testSqlInject() {
  104.     //queryDB("abc' or 1 = 1 #")
  105.     //queryDB("name=abc' and (select count(*) from user ) < 10#")
  106.     //queryDB("name=123' union select *from user #")
  107.     queryDBBySqlx("name=123' union select *from user #")
  108. }
  109.  
  110. func main() {
  111.  
  112.     err := initDb()
  113.     if err != nil {
  114.         fmt.Printf("init db failed, err:%v\n", err)
  115.         return
  116.     }
  117.  
  118.     //testQuery()
  119.     //testQueryMulti()
  120.     //testUpdate()
  121.     testSqlInject()
  122. }

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