fix index col compare case sensitive bug

  CREATE TABLE test_id (
    ID int,
    PRIMARY KEY (`ID`)
  )
  SELECT * FROM test_id WHERE id=1;

  fix explain NULL able column bug

  +----+-------------+-------+------------+------+---------------+------+---------+------+------+----------+--------------------------------+
  | id | select_type | table | partitions | type | possible_keys | key  | key_len | ref  | rows | filtered | Extra                          |
  +----+-------------+-------+------------+------+---------------+------+---------+------+------+----------+--------------------------------+
  |  1 | SIMPLE      | NULL  | NULL       | NULL | NULL          | NULL | NULL    | NULL | NULL |     NULL | no matching row in const table |
  +----+-------------+-------+------------+------+---------------+------+---------+------+------+----------+--------------------------------+

common/config.go

@@ -121,7 +121,7 @@ type Configuration struct {
 	ExplainWarnAccessType  []string `yaml:"explain-warn-access-type"` // 哪些 access type 不建议使用
 	ExplainMaxKeyLength    int      `yaml:"explain-max-keys"`         // 最大 key_len
 	ExplainMinPossibleKeys int      `yaml:"explain-min-keys"`         // 最小 possible_keys 警告
-	ExplainMaxRows         int      `yaml:"explain-max-rows"`         // 最大扫描行数警告
+	ExplainMaxRows         int64    `yaml:"explain-max-rows"`         // 最大扫描行数警告
 	ExplainWarnExtra       []string `yaml:"explain-warn-extra"`       // 哪些 extra 信息会给警告
 	ExplainMaxFiltered     float64  `yaml:"explain-max-filtered"`     // filtered 大于该配置给出警告
 	ExplainWarnScalability []string `yaml:"explain-warn-scalability"` // 复杂度警告名单
@@ -641,7 +641,7 @@ func readCmdFlags() error {
 	explainWarnAccessType := flag.String("explain-warn-access-type", strings.Join(Config.ExplainWarnAccessType, ","), "ExplainWarnAccessType, 哪些access type不建议使用")
 	explainMaxKeyLength := flag.Int("explain-max-keys", Config.ExplainMaxKeyLength, "ExplainMaxKeyLength, 最大key_len")
 	explainMinPossibleKeys := flag.Int("explain-min-keys", Config.ExplainMinPossibleKeys, "ExplainMinPossibleKeys, 最小possible_keys警告")
-	explainMaxRows := flag.Int("explain-max-rows", Config.ExplainMaxRows, "ExplainMaxRows, 最大扫描行数警告")
+	explainMaxRows := flag.Int64("explain-max-rows", Config.ExplainMaxRows, "ExplainMaxRows, 最大扫描行数警告")
 	explainWarnExtra := flag.String("explain-warn-extra", strings.Join(Config.ExplainWarnExtra, ","), "ExplainWarnExtra, 哪些extra信息会给警告")
 	explainMaxFiltered := flag.Float64("explain-max-filtered", Config.ExplainMaxFiltered, "ExplainMaxFiltered, filtered大于该配置给出警告")
 	explainWarnScalability := flag.String("explain-warn-scalability", strings.Join(Config.ExplainWarnScalability, ","), "ExplainWarnScalability, 复杂度警告名单, 支持O(n),O(log n),O(1),O(?)")

common/example_test.go

@@ -42,13 +42,16 @@ func ExampleIsColsPart() {
 	b := []*Column{{Name: "1"}, {Name: "2"}}
 	c := []*Column{{Name: "1"}, {Name: "3"}}
 	d := []*Column{{Name: "1"}, {Name: "2"}, {Name: "3"}, {Name: "4"}}
+	id := []*Column{{Name: "id"}}
+	iD := []*Column{{Name: "iD"}}
 
 	ab := IsColsPart(a, b)
 	ac := IsColsPart(a, c)
 	ad := IsColsPart(a, d)
+	idiD := IsColsPart(id, iD) // 大小写对比
 
-	fmt.Println(ab, ac, ad)
-	// Output: true false true
+	fmt.Println(ab, ac, ad, idiD)
+	// Output: true false true true
 	Log.Debug("Exiting function: %s", GetFunctionName())
 }
 

common/meta.go

@@ -93,7 +93,9 @@ func IsColsPart(a, b []*Column) bool {
 	}
 
 	for i := 0; i < times; i++ {
-		if a[i].DB != b[i].DB || a[i].Table != b[i].Table || a[i].Name != b[i].Name {
+		if strings.ToLower(a[i].DB) != strings.ToLower(b[i].DB) ||
+			strings.ToLower(a[i].Table) != strings.ToLower(b[i].Table) ||
+			strings.ToLower(a[i].Name) != strings.ToLower(b[i].Name) {
 			return false
 		}
 	}

database/explain.go

@@ -84,7 +84,7 @@ type ExplainRow struct {
 	Key          string
 	KeyLen       string // 索引长度，如果发生了index_merge， KeyLen 格式为 N,N，所以不能定义为整型
 	Ref          []string
-	Rows         int
+	Rows         int64
 	Filtered     float64 // 5.6 JSON, 5.7+, 5.5 EXTENDED
 	Scalability  string  // O(1), O(n), O(log n), O(log n)+
 	Extra        string
@@ -131,7 +131,7 @@ type ExplainJSONTable struct {
 	UsedKeyParts             []string                            `json:"used_key_parts"`
 	KeyLength                string                              `json:"key_length"`
 	Ref                      []string                            `json:"ref"`
-	RowsExaminedPerScan      int                                 `json:"rows_examined_per_scan"`
+	RowsExaminedPerScan      int64                               `json:"rows_examined_per_scan"`
 	RowsProducedPerJoin      int                                 `json:"rows_produced_per_join"`
 	Filtered                 string                              `json:"filtered"`
 	UsingIndex               bool                                `json:"using_index"`
@@ -318,6 +318,7 @@ var ExplainAccessType = map[string]string{
 
 // ExplainScalability ACCESS TYPE对应的运算复杂度 [AccessType]scalability map
 var ExplainScalability = map[string]string{
+	"NULL":            "NULL",
 	"ALL":             "O(n)",
 	"index":           "O(n)",
 	"range":           "O(log n)+",
@@ -784,7 +785,7 @@ func parseTraditionalExplainText(content string) (explainRows []ExplainRow, err
 	colsMap := make(map[string]string)
 	for _, l := range lines[3:] {
 		var keylen string
-		var rows int
+		var rows int64
 		var filtered float64
 		var partitions string
 		// 跳过分割线
@@ -816,7 +817,7 @@ func parseTraditionalExplainText(content string) (explainRows []ExplainRow, err
 
 		keylen = colsMap["key_len"]
 
-		rows, err = strconv.Atoi(colsMap["Rows"])
+		rows, err = strconv.ParseInt(colsMap["Rows"], 10, 64)
 		if err != nil {
 			rows = 0
 		}
@@ -908,7 +909,7 @@ func parseVerticalExplainText(content string) (explainRows []ExplainRow, err err
 		}
 		if strings.HasPrefix(l, "Rows:") {
 			rows := strings.TrimPrefix(l, "Rows: ")
-			explainRow.Rows, err = strconv.Atoi(rows)
+			explainRow.Rows, err = strconv.ParseInt(rows, 10, 64)
 			if err != nil {
 				explainRow.Rows = 0
 			}
@@ -957,15 +958,21 @@ func ParseExplainResult(res QueryResult, formatType int) (exp *ExplainInfo, err
 	}
 
 	/*
-		+----+-------------+-------+------------+------+---------------+------+---------+------+------+----------+-------+
-		| id | select_type | table | partitions | type | possible_keys | key  | key_len | ref  | rows | filtered | Extra |
-		+----+-------------+-------+------------+------+---------------+------+---------+------+------+----------+-------+
-		|  1 | SIMPLE      | film  | NULL       | ALL  | NULL          | NULL | NULL    | NULL | 1000 |   100.00 | NULL  |
-		+----+-------------+-------+------------+------+---------------+------+---------+------+------+----------+-------+
+				+----+-------------+-------+------------+------+---------------+------+---------+------+------+----------+-------+
+				| id | select_type | table | partitions | type | possible_keys | key  | key_len | ref  | rows | filtered | Extra |
+				+----+-------------+-------+------------+------+---------------+------+---------+------+------+----------+-------+
+				|  1 | SIMPLE      | film  | NULL       | ALL  | NULL          | NULL | NULL    | NULL | 1000 |   100.00 | NULL  |
+				+----+-------------+-------+------------+------+---------------+------+---------+------+------+----------+-------+
+
+		        +----+-------------+-------+------------+------+---------------+------+---------+------+------+----------+--------------------------------+
+		        | id | select_type | table | partitions | type | possible_keys | key  | key_len | ref  | rows | filtered | Extra                          |
+		        +----+-------------+-------+------------+------+---------------+------+---------+------+------+----------+--------------------------------+
+		        |  1 | SIMPLE      | NULL  | NULL       | NULL | NULL          | NULL | NULL    | NULL | NULL |     NULL | no matching row in const table |
+		        +----+-------------+-------+------------+------+---------------+------+---------+------+------+----------+--------------------------------+
 	*/
 
 	// Different MySQL version has different columns define
-	var selectType, table, partitions, accessType, possibleKeys, key, keyLen, ref, extra []byte
+	var selectType, table, partitions, accessType, possibleKeys, key, keyLen, ref, extra, rows, filtered []byte
 	expRow := ExplainRow{}
 	explainFields := make([]interface{}, 0)
 	fields := map[string]interface{}{
@@ -978,8 +985,8 @@ func ParseExplainResult(res QueryResult, formatType int) (exp *ExplainInfo, err
 		"key":           &key,
 		"key_len":       &keyLen,
 		"ref":           &ref,
-		"rows":          &expRow.Rows,
-		"filtered":      &expRow.Filtered,
+		"rows":          &rows,
+		"filtered":      &filtered,
 		"Extra":         &extra,
 	}
 	cols, err := res.Rows.Columns()
@@ -1009,6 +1016,8 @@ func ParseExplainResult(res QueryResult, formatType int) (exp *ExplainInfo, err
 		expRow.Key = NullString(key)
 		expRow.KeyLen = NullString(keyLen)
 		expRow.Ref = strings.Split(NullString(ref), ",")
+		expRow.Rows = NullInt(rows)
+		expRow.Filtered = NullFloat(filtered)
 		expRow.Extra = NullString(extra)
 
 		// MySQL bug: https://bugs.mysql.com/bug.php?id=34124
@@ -1115,7 +1124,9 @@ func PrintMarkdownExplainTable(exp *ExplainInfo) string {
 			}
 			scalability := row.Scalability
 			for _, s := range common.Config.ExplainWarnScalability {
-				scalability = "☠️ **" + s + "**"
+				if s == scalability {
+					scalability = "☠️ **" + s + "**"
+				}
 			}
 			buf = append(buf, fmt.Sprintln("|", row.ID, " |",
 				common.MarkdownEscape(row.SelectType),

database/mysql.go

@@ -319,6 +319,24 @@ func NullString(buf []byte) string {
 	return string(buf)
 }
 
+// NullFloat null able float
+func NullFloat(buf []byte) float64 {
+	if buf == nil {
+		return 0
+	}
+	f, _ := strconv.ParseFloat(string(buf), 64)
+	return f
+}
+
+// NullInt null able int
+func NullInt(buf []byte) int64 {
+	if buf == nil {
+		return 0
+	}
+	i, _ := strconv.ParseInt(string(buf), 10, 64)
+	return i
+}
+
 // quoteEscape sql_mode=no_backslash_escapes
 func quoteEscape(source string) string {
 	var buf bytes.Buffer