Postgresql 为什么在插入postgres后,即使插入成功,我也会得到ErrNoRows(“sql:结果集中没有行”)?
我与golang postgres合作:Postgresql 为什么在插入postgres后,即使插入成功,我也会得到ErrNoRows(“sql:结果集中没有行”)?,postgresql,go,pq,Postgresql,Go,Pq,我与golang postgres合作: "database/sql" _ "github.com/lib/pq" 我在做什么: selectQuery = `select task_id, creation_date, times_x_ran, a_count, b_count, c_count, d_count, e_count from reports where creation_date
"database/sql"
_ "github.com/lib/pq"
我在做什么:
selectQuery = `select task_id, creation_date, times_x_ran,
a_count, b_count, c_count, d_count, e_count
from reports where creation_date = $1 and task_id = $2`
insertQuery = `insert into reports
(creation_date, creation_time, last_modified, task_id, times_x_ran, times_y_ran, a, b, c, d, e, x_errors, y_errors)
values
($1, $2, $3, $4,
1, 0,
0, 0, 0, 0, 0,
'', '' )`
我运行一个select查询。
如果我在选择时没有得到任何条目,我会继续插入一个条目。
其他,更新,或其他
问题是,每次insert返回ErrNoRows(“sql:结果集中没有行”),即使我在数据库中看到insert成功,并且添加了行
另外,lastInsertID始终保持为0,而如果我签入DB,则它有一个实际值(例如,131)
似乎代码中下面注释2附近的错误被缓存在某个地方,然后再次显示
// 1. Select first
sQueryStmt, sPrepErr := db.Prepare(selectQuery)
if sPrepErr != nil {
glog.V(3).Infof("selectQuery prepare failed. err: %v", sPrepErr)
return sPrepErr
}
queryErr := sQueryStmt.QueryRow(today, itemID).Scan(&a, &b, &c, &d, &e, &f, &g, &h, &i, &j)
if queryErr != nil {
// 2. Getting ErrNoRows here is expected, for the first entry
if queryErr == sql.ErrNoRows {
glog.V(3).Infof("selectQuery returned no results. err: %v", queryErr)
var lastInsertID int
iQueryStmt, iPrepErr := db.Prepare(insertQuery)
if iPrepErr != nil {
glog.V(3).Infof("insertQuery prepare failed. err: %v", iPrepErr)
return iPrepErr
}
insertErr := iQueryStmt.QueryRow(today, today, today, taskID).Scan(&lastInsertID)
if insertErr != nil {
// 3. Somehow, even after row is correctly being created, I am getting insertErr as "sql: no rows in result set" here
glog.V(3).Infof("insertQuery failed. err: %v", insertErr)
} else {
// control never comes to this part.
glog.V(3).Infof("insertQuery Successful. lastInsertID: %v", lastInsertID)
}
} else {
glog.V(3).Infof("Couldn't run query on Postgres database. err: %v", queryErr)
return queryErr
}
}
在数据库/sql内部调试表明,它在以下代码块中返回此错误:
if !r.rows.Next() {
if err := r.rows.Err(); err != nil {
return err
}
return ErrNoRows
}
但是每次,如果我签入数据库,数据总是已经插入
编辑:
selectQuery = `select task_id, creation_date, times_x_ran,
a_count, b_count, c_count, d_count, e_count
from reports where creation_date = $1 and task_id = $2`
insertQuery = `insert into reports
(creation_date, creation_time, last_modified, task_id, times_x_ran, times_y_ran, a, b, c, d, e, x_errors, y_errors)
values
($1, $2, $3, $4,
1, 0,
0, 0, 0, 0, 0,
'', '' )`
你已经有效地问了两个问题,所以我将回答这两个问题:
您能显示查询的内容吗?插入查询/选择查询字符串?我这样问是因为如果你的insertQuery没有返回子句,你会得到这个错误,也就是说,没有要扫描的内容。更新了问题。你的insert查询没有返回任何内容,所以调用scan(&lastInserteded)总是会得到这个错误。这是你需要的,很好,明白了。谢谢你,伙计。我想我只需要加上“返回id”