go-sql-driver/mysql

Return useful error when attempting to reuse a blocked connection

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#526 建立於 2016年12月8日

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 (10 留言) (5 反應) (0 負責人)Go (9,946 star) (1,789 fork)batch import
help wanted

描述

Issue description

the latest version: 1.3.

Prepare one statement and execute it on one transaction, keep rows open. Error happens when trying to prepare another statement: [mysql] 2016/12/08 15:45:57 packets.go:431: busy buffer

I see issue#314 which was similiar with the problem and closed. Looks like this problem not fixed in 1.3.

Example code

func query(db *sql.DB) {
	var (
		tx    *sql.Tx
		stmt1 *sql.Stmt
		stmt2 *sql.Stmt
		rs1   *sql.Rows
		rs2   *sql.Rows
	)

	tx, _ = db.Begin()
	stmt1, _ = tx.Prepare("select f1, f2 from test where f2 = 11")
	rs1, _ = stmt1.Query()
	rs1.Next()

	stmt2, _ = tx.Prepare("select f2 from test where f2 = 111")  // error here
	rs2, _ = stmt2.Query()
	rs2.Next()

}

Error log

[mysql] 2016/12/08 15:45:57 packets.go:431: busy buffer

Configuration

*Driver version:1.3

Go version: go version go1.7.1 windows/amd64,go version go1.7.4 linux/amd64

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技術棧
go
領域
backenddatabase
議題類型
bug
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clear
前置要求
Go programmingdatabase/sql packageMySQL driver internals
新手友善度1-100 的估計分數，表示該議題對首次貢獻者的友善程度。
45
研究方向
The bug is about a busy buffer error when calling Prepare on a transaction that already has active rows. The error source is packets.go:431. To fix, the driver should detect that the connection buffer is busy and return a descriptive error like 'connection is busy with another result set'. Look at how conn.go manages the buffer state and ensure it is reset properly after rows are closed. Also review issue #314 for prior discussion.
Return useful error when attempting to reuse a blocked connection · go-sql-driver/mysql#526 | Good First Issue