Better idomatic go for query building

Author: Areson

metrics/error/query.go

@@ -36,17 +36,18 @@ func ErrorsQuery(dom blip.Domain, baseQuery string, groupBy string, subDomain st
 	}, nil
 }
 
-func initWhere(where *string) {
-	if *where == "" {
-		*where = " WHERE"
+// setAnd is a helper function to determine if the "AND" clause should be added to the WHERE clause.
+func setAnd(where strings.Builder) string {
+	if where.Len() == 0 {
+		return ""
 	} else {
-		*where = *where + " AND"
+		return " AND"
 	}
 }
 
 func setWhere(dom blip.Domain, subDomain string) (string, []any, error) {
 	// Initialize the where clause once if we need it
-	var where string
+	var where strings.Builder
 	var params []any = make([]any, 0)
 	var errorNum []any = make([]any, 0)
 	var errorName []any = make([]any, 0)
@@ -64,7 +65,7 @@ func setWhere(dom blip.Domain, subDomain string) (string, []any, error) {
 			return "", nil, fmt.Errorf("invalid option %s", dom.Options[OPT_ALL])
 		}
 
-		initWhere(&where)
+		where.WriteString(setAnd(where))
 
 		for _, metric := range dom.Metrics {
 			if i, err := strconv.Atoi(metric); err == nil {
@@ -85,35 +86,46 @@ func setWhere(dom blip.Domain, subDomain string) (string, []any, error) {
 			params = append(params, errorName...)
 		}
 
-		where = where + fmt.Sprintf(" (%s)", strings.Join(errorConditions, conj))
+		where.WriteString(fmt.Sprintf(" (%s)", strings.Join(errorConditions, conj)))
 	} else {
 		// Exclude NULL error numbers
-		initWhere(&where)
-		where = where + " ERROR_NUMBER IS NOT NULL"
+		where.WriteString(setAnd(where))
+		where.WriteString(" ERROR_NUMBER IS NOT NULL")
 	}
 
 	// Handle include/exclude filters based on the collector type
+	var subWhere string
+	var subParams []any = make([]any, 0)
+
 	switch subDomain {
 	case SUB_DOMAIN_ACCOUNT:
-		params = addAccountFilters(&where, params, dom)
+		subWhere, subParams = getAccountFilters(dom)
 	case SUB_DOMAIN_USER:
-		params = addUserFilters(&where, params, dom)
+		subWhere, subParams = getUserFilters(dom)
 	case SUB_DOMAIN_HOST:
-		params = addHostFilters(&where, params, dom)
+		subWhere, subParams = getHostFilters(dom)
 	case SUB_DOMAIN_THREAD:
-		params = addThreadFilters(&where, params, dom)
+		subWhere, subParams = getThreadFilters(dom)
 	case SUB_DOMAIN_GLOBAL:
 		// No additional filters needed
 	}
 
+	if len(subWhere) > 0 {
+		where.WriteString(setAnd(where))
+		where.WriteString(subWhere)
+		params = append(params, subParams...)
+	}
+
 	// Exclude errors without any errors raised
-	initWhere(&where)
-	where = where + " SUM_ERROR_RAISED > 0"
+	where.WriteString(setAnd(where))
+	where.WriteString(" SUM_ERROR_RAISED > 0")
 
-	return where, params, nil
+	return " WHERE" + where.String(), params, nil
 }
 
-func addAccountFilters(where *string, params []any, dom blip.Domain) []any {
+func getAccountFilters(dom blip.Domain) (string, []any) {
+	var where strings.Builder
+	var params []any = []any{}
 	hasValidTokens := false
 	var conjunction, inOp string
 	onlyUser := []string{}
@@ -154,8 +166,8 @@ func addAccountFilters(where *string, params []any, dom blip.Domain) []any {
 	}
 
 	if hasValidTokens {
-		initWhere(where)
-		*where = *where + " ("
+		where.WriteString(setAnd(where))
+		where.WriteString(" (")
 		parts := make([]string, 0, 3)
 
 		if len(onlyAccount) > 0 {
@@ -175,73 +187,84 @@ func addAccountFilters(where *string, params []any, dom blip.Domain) []any {
 			params = append(params, sqlutil.ToInterfaceArray(onlyHost)...)
 		}
 
-		*where = *where + strings.Join(parts, fmt.Sprintf(" %s ", conjunction)) + ")"
+		where.WriteString(strings.Join(parts, fmt.Sprintf(" %s ", conjunction)))
+		where.WriteString(")")
 	}
 
 	// Ensure user and host are not NULL
-	initWhere(where)
-	*where = *where + " USER IS NOT NULL AND HOST IS NOT NULL"
+	where.WriteString(setAnd(where))
+	where.WriteString(" USER IS NOT NULL AND HOST IS NOT NULL")
 
-	return params
+	return where.String(), params
 }
 
-func addUserFilters(where *string, params []any, dom blip.Domain) []any {
+func getUserFilters(dom blip.Domain) (string, []any) {
+	var where strings.Builder
+	var params []any = []any{}
+
 	if include := dom.Options[OPT_INCLUDE]; include != "" {
-		initWhere(where)
+		where.WriteString(setAnd(where))
 		users := strings.Split(include, ",")
-		*where = *where + fmt.Sprintf(" USER IN (%s)", sqlutil.PlaceholderList(len(users)))
+
+		where.WriteString(fmt.Sprintf(" USER IN (%s)", sqlutil.PlaceholderList(len(users))))
 		params = append(params, sqlutil.ToInterfaceArray(users)...)
 	} else if exclude := dom.Options[OPT_EXCLUDE]; exclude != "" {
-		initWhere(where)
+		where.WriteString(setAnd(where))
 		users := strings.Split(exclude, ",")
-		*where = *where + fmt.Sprintf(" USER NOT IN (%s)", sqlutil.PlaceholderList(len(users)))
+		where.WriteString(fmt.Sprintf(" USER NOT IN (%s)", sqlutil.PlaceholderList(len(users))))
 		params = append(params, sqlutil.ToInterfaceArray(users)...)
 	} else {
 		// Exclude NULL users
-		initWhere(where)
-		*where = *where + " USER IS NOT NULL"
+		where.WriteString(setAnd(where))
+		where.WriteString(" USER IS NOT NULL")
 	}
 
-	return params
+	return where.String(), params
 }
 
-func addHostFilters(where *string, params []any, dom blip.Domain) []any {
+func getHostFilters(dom blip.Domain) (string, []any) {
+	var where strings.Builder
+	var params []any = []any{}
+
 	if include := dom.Options[OPT_INCLUDE]; include != "" {
-		initWhere(where)
+		where.WriteString(setAnd(where))
 		hosts := strings.Split(include, ",")
 
-		*where = *where + fmt.Sprintf(" HOST IN (%s)", sqlutil.PlaceholderList(len(hosts)))
+		where.WriteString(fmt.Sprintf(" HOST IN (%s)", sqlutil.PlaceholderList(len(hosts))))
 		params = append(params, sqlutil.ToInterfaceArray(hosts)...)
 	} else if exclude := dom.Options[OPT_EXCLUDE]; exclude != "" {
-		initWhere(where)
+		where.WriteString(setAnd(where))
 		hosts := strings.Split(exclude, ",")
-		*where = *where + fmt.Sprintf(" HOST NOT IN (%s)", sqlutil.PlaceholderList(len(hosts)))
+		where.WriteString(fmt.Sprintf(" HOST NOT IN (%s)", sqlutil.PlaceholderList(len(hosts))))
 		params = append(params, sqlutil.ToInterfaceArray(hosts)...)
 	} else {
 		// Exclude NULL hosts
-		initWhere(where)
-		*where = *where + " HOST IS NOT NULL"
+		where.WriteString(setAnd(where))
+		where.WriteString(" HOST IS NOT NULL")
 	}
 
-	return params
+	return where.String(), params
 }
 
-func addThreadFilters(where *string, params []any, dom blip.Domain) []any {
+func getThreadFilters(dom blip.Domain) (string, []any) {
+	var where strings.Builder
+	var params []any = []any{}
+
 	if include := dom.Options[OPT_INCLUDE]; include != "" {
-		initWhere(where)
+		where.WriteString(setAnd(where))
 		threads := strings.Split(include, ",")
-		*where = *where + fmt.Sprintf(" THREAD_ID IN (%s)", sqlutil.PlaceholderList(len(threads)))
+		where.WriteString(fmt.Sprintf(" THREAD_ID IN (%s)", sqlutil.PlaceholderList(len(threads))))
 		params = append(params, sqlutil.ToInterfaceArray(threads)...)
 	} else if exclude := dom.Options[OPT_EXCLUDE]; exclude != "" {
-		initWhere(where)
+		where.WriteString(setAnd(where))
 		threads := strings.Split(exclude, ",")
-		*where = *where + fmt.Sprintf(" THREAD_ID NOT IN (%s)", sqlutil.PlaceholderList(len(threads)))
+		where.WriteString(fmt.Sprintf(" THREAD_ID NOT IN (%s)", sqlutil.PlaceholderList(len(threads))))
 		params = append(params, sqlutil.ToInterfaceArray(threads)...)
 	} else {
 		// Exclude NULL thread IDs
-		initWhere(where)
-		*where = *where + " THREAD_ID IS NOT NULL"
+		where.WriteString(setAnd(where))
+		where.WriteString(" THREAD_ID IS NOT NULL")
 	}
 
-	return params
+	return where.String(), params
 }