Remove strict mode (go-sql-driver#676)

* Remove strict mode

Fixes go-sql-driver#556 go-sql-driver#602 go-sql-driver#635
Closes go-sql-driver#609

* dsn: panic in case of strict mode

Author: julienschmidt

README.md

@@ -294,20 +294,6 @@ supposed to happen, setting this on some MySQL providers (such as AWS Aurora)
 is safer for failovers.
 
 
-##### `strict`
-
-```
-Type:           bool
-Valid Values:   true, false
-Default:        false
-```
-
-`strict=true` enables a driver-side strict mode in which MySQL warnings are treated as errors. This mode should not be used in production as it may lead to data corruption in certain situations.
-
-A server-side strict mode, which is safe for production use, can be set via the [`sql_mode`](https://dev.mysql.com/doc/refman/5.7/en/sql-mode.html) system variable.
-
-By default MySQL also treats notes as warnings. Use [`sql_notes=false`](http://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html#sysvar_sql_notes) to ignore notes.
-
 ##### `timeout`
 
 ```
@@ -317,6 +303,7 @@ Default:        OS default
 
 Timeout for establishing connections, aka dial timeout. The value must be a decimal number with a unit suffix (*"ms"*, *"s"*, *"m"*, *"h"*), such as *"30s"*, *"0.5m"* or *"1m30s"*.
 
+
 ##### `tls`
 
 ```
@@ -327,6 +314,7 @@ Default:        false
 
 `tls=true` enables TLS / SSL encrypted connection to the server. Use `skip-verify` if you want to use a self-signed or invalid certificate (server side). Use a custom value registered with [`mysql.RegisterTLSConfig`](https://godoc.org/github.com/go-sql-driver/mysql#RegisterTLSConfig).
 
+
 ##### `writeTimeout`
 
 ```

benchmark_test.go

@@ -48,11 +48,7 @@ func initDB(b *testing.B, queries ...string) *sql.DB {
 	db := tb.checkDB(sql.Open("mysql", dsn))
 	for _, query := range queries {
 		if _, err := db.Exec(query); err != nil {
-			if w, ok := err.(MySQLWarnings); ok {
-				b.Logf("warning on %q: %v", query, w)
-			} else {
-				b.Fatalf("error on %q: %v", query, err)
-			}
+			b.Fatalf("error on %q: %v", query, err)
 		}
 	}
 	return db

connection.go

@@ -40,7 +40,6 @@ type mysqlConn struct {
 	status           statusFlag
 	sequence         uint8
 	parseTime        bool
-	strict           bool
 
 	// for context support (Go 1.8+)
 	watching bool

driver.go

@@ -64,7 +64,6 @@ func (d MySQLDriver) Open(dsn string) (driver.Conn, error) {
 		return nil, err
 	}
 	mc.parseTime = mc.cfg.ParseTime
-	mc.strict = mc.cfg.Strict
 
 	// Connect to Server
 	if dial, ok := dials[mc.cfg.Net]; ok {

driver_test.go

@@ -63,7 +63,7 @@ func init() {
 	addr = env("MYSQL_TEST_ADDR", "localhost:3306")
 	dbname = env("MYSQL_TEST_DBNAME", "gotest")
 	netAddr = fmt.Sprintf("%s(%s)", prot, addr)
-	dsn = fmt.Sprintf("%s:%s@%s/%s?timeout=30s&strict=true", user, pass, netAddr, dbname)
+	dsn = fmt.Sprintf("%s:%s@%s/%s?timeout=30s", user, pass, netAddr, dbname)
 	c, err := net.Dial(prot, addr)
 	if err == nil {
 		available = true
@@ -1170,82 +1170,6 @@ func TestFoundRows(t *testing.T) {
 	})
 }
 
-func TestStrict(t *testing.T) {
-	// ALLOW_INVALID_DATES to get rid of stricter modes - we want to test for warnings, not errors
-	relaxedDsn := dsn + "&sql_mode='ALLOW_INVALID_DATES,NO_AUTO_CREATE_USER'"
-	// make sure the MySQL version is recent enough with a separate connection
-	// before running the test
-	conn, err := MySQLDriver{}.Open(relaxedDsn)
-	if conn != nil {
-		conn.Close()
-	}
-	// Error 1231: Variable 'sql_mode' can't be set to the value of
-	// 'ALLOW_INVALID_DATES' => skip test, MySQL server version is too old
-	maybeSkip(t, err, 1231)
-	runTests(t, relaxedDsn, func(dbt *DBTest) {
-		dbt.mustExec("CREATE TABLE test (a TINYINT NOT NULL, b CHAR(4))")
-
-		var queries = [...]struct {
-			in    string
-			codes []string
-		}{
-			{"DROP TABLE IF EXISTS no_such_table", []string{"1051"}},
-			{"INSERT INTO test VALUES(10,'mysql'),(NULL,'test'),(300,'Open Source')", []string{"1265", "1048", "1264", "1265"}},
-		}
-		var err error
-
-		var checkWarnings = func(err error, mode string, idx int) {
-			if err == nil {
-				dbt.Errorf("expected STRICT error on query [%s] %s", mode, queries[idx].in)
-			}
-
-			if warnings, ok := err.(MySQLWarnings); ok {
-				var codes = make([]string, len(warnings))
-				for i := range warnings {
-					codes[i] = warnings[i].Code
-				}
-				if len(codes) != len(queries[idx].codes) {
-					dbt.Errorf("unexpected STRICT error count on query [%s] %s: Wanted %v, Got %v", mode, queries[idx].in, queries[idx].codes, codes)
-				}
-
-				for i := range warnings {
-					if codes[i] != queries[idx].codes[i] {
-						dbt.Errorf("unexpected STRICT error codes on query [%s] %s: Wanted %v, Got %v", mode, queries[idx].in, queries[idx].codes, codes)
-						return
-					}
-				}
-
-			} else {
-				dbt.Errorf("unexpected error on query [%s] %s: %s", mode, queries[idx].in, err.Error())
-			}
-		}
-
-		// text protocol
-		for i := range queries {
-			_, err = dbt.db.Exec(queries[i].in)
-			checkWarnings(err, "text", i)
-		}
-
-		var stmt *sql.Stmt
-
-		// binary protocol
-		for i := range queries {
-			stmt, err = dbt.db.Prepare(queries[i].in)
-			if err != nil {
-				dbt.Errorf("error on preparing query %s: %s", queries[i].in, err.Error())
-			}
-
-			_, err = stmt.Exec()
-			checkWarnings(err, "binary", i)
-
-			err = stmt.Close()
-			if err != nil {
-				dbt.Errorf("error on closing stmt for query %s: %s", queries[i].in, err.Error())
-			}
-		}
-	})
-}
-
 func TestTLS(t *testing.T) {
 	tlsTest := func(dbt *DBTest) {
 		if err := dbt.db.Ping(); err != nil {
@@ -1762,7 +1686,7 @@ func TestCustomDial(t *testing.T) {
 		return net.Dial(prot, addr)
 	})
 
-	db, err := sql.Open("mysql", fmt.Sprintf("%s:%s@mydial(%s)/%s?timeout=30s&strict=true", user, pass, addr, dbname))
+	db, err := sql.Open("mysql", fmt.Sprintf("%s:%s@mydial(%s)/%s?timeout=30s", user, pass, addr, dbname))
 	if err != nil {
 		t.Fatalf("error connecting: %s", err.Error())
 	}
@@ -1859,7 +1783,7 @@ func TestUnixSocketAuthFail(t *testing.T) {
 			}
 		}
 		t.Logf("socket: %s", socket)
-		badDSN := fmt.Sprintf("%s:%s@unix(%s)/%s?timeout=30s&strict=true", user, badPass, socket, dbname)
+		badDSN := fmt.Sprintf("%s:%s@unix(%s)/%s?timeout=30s", user, badPass, socket, dbname)
 		db, err := sql.Open("mysql", badDSN)
 		if err != nil {
 			t.Fatalf("error connecting: %s", err.Error())

dsn.go

@@ -55,7 +55,6 @@ type Config struct {
 	MultiStatements         bool // Allow multiple statements in one query
 	ParseTime               bool // Parse time values to time.Time
 	RejectReadOnly          bool // Reject read-only connections
-	Strict                  bool // Return warnings as errors
 }
 
 // FormatDSN formats the given Config into a DSN string which can be passed to
@@ -206,15 +205,6 @@ func (cfg *Config) FormatDSN() string {
 		}
 	}
 
-	if cfg.Strict {
-		if hasParam {
-			buf.WriteString("&strict=true")
-		} else {
-			hasParam = true
-			buf.WriteString("?strict=true")
-		}
-	}
-
 	if cfg.Timeout > 0 {
 		if hasParam {
 			buf.WriteString("&timeout=")
@@ -502,11 +492,7 @@ func parseDSNParams(cfg *Config, params string) (err error) {
 
 		// Strict mode
 		case "strict":
-			var isBool bool
-			cfg.Strict, isBool = readBool(value)
-			if !isBool {
-				return errors.New("invalid bool value: " + value)
-			}
+			panic("strict mode has been removed. See https://github.com/go-sql-driver/mysql/wiki/strict-mode")
 
 		// Dial Timeout
 		case "timeout":

errors.go

@@ -9,10 +9,8 @@
 package mysql
 
 import (
-	"database/sql/driver"
 	"errors"
 	"fmt"
-	"io"
 	"log"
 	"os"
 )
@@ -65,74 +63,3 @@ type MySQLError struct {
 func (me *MySQLError) Error() string {
 	return fmt.Sprintf("Error %d: %s", me.Number, me.Message)
 }
-
-// MySQLWarnings is an error type which represents a group of one or more MySQL
-// warnings
-type MySQLWarnings []MySQLWarning
-
-func (mws MySQLWarnings) Error() string {
-	var msg string
-	for i, warning := range mws {
-		if i > 0 {
-			msg += "\r\n"
-		}
-		msg += fmt.Sprintf(
-			"%s %s: %s",
-			warning.Level,
-			warning.Code,
-			warning.Message,
-		)
-	}
-	return msg
-}
-
-// MySQLWarning is an error type which represents a single MySQL warning.
-// Warnings are returned in groups only. See MySQLWarnings
-type MySQLWarning struct {
-	Level   string
-	Code    string
-	Message string
-}
-
-func (mc *mysqlConn) getWarnings() (err error) {
-	rows, err := mc.Query("SHOW WARNINGS", nil)
-	if err != nil {
-		return
-	}
-
-	var warnings = MySQLWarnings{}
-	var values = make([]driver.Value, 3)
-
-	for {
-		err = rows.Next(values)
-		switch err {
-		case nil:
-			warning := MySQLWarning{}
-
-			if raw, ok := values[0].([]byte); ok {
-				warning.Level = string(raw)
-			} else {
-				warning.Level = fmt.Sprintf("%s", values[0])
-			}
-			if raw, ok := values[1].([]byte); ok {
-				warning.Code = string(raw)
-			} else {
-				warning.Code = fmt.Sprintf("%s", values[1])
-			}
-			if raw, ok := values[2].([]byte); ok {
-				warning.Message = string(raw)
-			} else {
-				warning.Message = fmt.Sprintf("%s", values[0])
-			}
-
-			warnings = append(warnings, warning)
-
-		case io.EOF:
-			return warnings
-
-		default:
-			rows.Close()
-			return
-		}
-	}
-}

packets.go

@@ -624,14 +624,7 @@ func (mc *mysqlConn) handleOkPacket(data []byte) error {
 	}
 
 	// warning count [2 bytes]
-	if !mc.strict {
-		return nil
-	}
 
-	pos := 1 + n + m + 2
-	if binary.LittleEndian.Uint16(data[pos:pos+2]) > 0 {
-		return mc.getWarnings()
-	}
 	return nil
 }
 
@@ -843,14 +836,7 @@ func (stmt *mysqlStmt) readPrepareResultPacket() (uint16, error) {
 		// Reserved [8 bit]
 
 		// Warning count [16 bit uint]
-		if !stmt.mc.strict {
-			return columnCount, nil
-		}
 
-		// Check for warnings count > 0, only available in MySQL > 4.1
-		if len(data) >= 12 && binary.LittleEndian.Uint16(data[10:12]) > 0 {
-			return columnCount, stmt.mc.getWarnings()
-		}
 		return columnCount, nil
 	}
 	return 0, err