chore(outputs.sql): Adapt default templates for ClickHouse (#16464)

plugins/outputs/sql/README.md

@@ -99,7 +99,11 @@ See the [CONFIGURATION.md][CONFIGURATION.md] for more details.
   ##  {TABLE} - table name as a quoted identifier
   ##  {TABLELITERAL} - table name as a quoted string literal
   ##  {COLUMNS} - column definitions (list of quoted identifiers and types)
+  ##  {TAG_COLUMN_NAMES} - tag column definitions (list of quoted identifiers)
+  ##  {TIMESTAMP_COLUMN_NAME} - the name of the time stamp column, as configured above
   # table_template = "CREATE TABLE {TABLE}({COLUMNS})"
+  ## NOTE: For the clickhouse driver the default is:
+  # table_template = "CREATE TABLE {TABLE}({COLUMNS}) ORDER BY ({TAG_COLUMN_NAMES}, {TIMESTAMP_COLUMN_NAME})"
 
   ## Table existence check template
   ## Available template variables:

plugins/outputs/sql/sample.conf

@@ -18,7 +18,11 @@
   ##  {TABLE} - table name as a quoted identifier
   ##  {TABLELITERAL} - table name as a quoted string literal
   ##  {COLUMNS} - column definitions (list of quoted identifiers and types)
+  ##  {TAG_COLUMN_NAMES} - tag column definitions (list of quoted identifiers)
+  ##  {TIMESTAMP_COLUMN_NAME} - the name of the time stamp column, as configured above
   # table_template = "CREATE TABLE {TABLE}({COLUMNS})"
+  ## NOTE: For the clickhouse driver the default is:
+  # table_template = "CREATE TABLE {TABLE}({COLUMNS}) ORDER BY ({TAG_COLUMN_NAMES}, {TIMESTAMP_COLUMN_NAME})"
 
   ## Table existence check template
   ## Available template variables:

plugins/outputs/sql/sql.go

@@ -150,6 +150,7 @@ func (p *SQL) deriveDatatype(value interface{}) string {
 
 func (p *SQL) generateCreateTable(metric telegraf.Metric) string {
 	columns := make([]string, 0, len(metric.TagList())+len(metric.FieldList())+1)
+	tagColumnNames := make([]string, 0, len(metric.TagList()))
 
 	if p.TimestampColumn != "" {
 		columns = append(columns, fmt.Sprintf("%s %s", quoteIdent(p.TimestampColumn), p.Convert.Timestamp))
@@ -157,6 +158,7 @@ func (p *SQL) generateCreateTable(metric telegraf.Metric) string {
 
 	for _, tag := range metric.TagList() {
 		columns = append(columns, fmt.Sprintf("%s %s", quoteIdent(tag.Key), p.Convert.Text))
+		tagColumnNames = append(tagColumnNames, quoteIdent(tag.Key))
 	}
 
 	var datatype string
@@ -169,6 +171,8 @@ func (p *SQL) generateCreateTable(metric telegraf.Metric) string {
 	query = strings.ReplaceAll(query, "{TABLE}", quoteIdent(metric.Name()))
 	query = strings.ReplaceAll(query, "{TABLELITERAL}", quoteStr(metric.Name()))
 	query = strings.ReplaceAll(query, "{COLUMNS}", strings.Join(columns, ","))
+	query = strings.ReplaceAll(query, "{TAG_COLUMN_NAMES}", strings.Join(tagColumnNames, ","))
+	query = strings.ReplaceAll(query, "{TIMESTAMP_COLUMN_NAME}", quoteIdent(p.TimestampColumn))
 
 	return query
 }
@@ -271,15 +275,30 @@ func (p *SQL) Write(metrics []telegraf.Metric) error {
 	return nil
 }
 
+func (p *SQL) Init() error {
+	if p.TableExistsTemplate == "" {
+		p.TableExistsTemplate = "SELECT 1 FROM {TABLE} LIMIT 1"
+	}
+	if p.TimestampColumn == "" {
+		p.TimestampColumn = "timestamp"
+	}
+	if p.TableTemplate == "" {
+		if p.Driver == "clickhouse" {
+			p.TableTemplate = "CREATE TABLE {TABLE}({COLUMNS}) ORDER BY ({TAG_COLUMN_NAMES}, {TIMESTAMP_COLUMN_NAME})"
+		} else {
+			p.TableTemplate = "CREATE TABLE {TABLE}({COLUMNS})"
+		}
+	}
+
+	return nil
+}
+
 func init() {
 	outputs.Add("sql", func() telegraf.Output { return newSQL() })
 }
 
 func newSQL() *SQL {
 	return &SQL{
-		TableTemplate:       "CREATE TABLE {TABLE}({COLUMNS})",
-		TableExistsTemplate: "SELECT 1 FROM {TABLE} LIMIT 1",
-		TimestampColumn:     "timestamp",
 		Convert: ConvertStruct{
 			Integer:         "INT",
 			Real:            "DOUBLE",

plugins/outputs/sql/sql_test.go

@@ -200,6 +200,7 @@ func TestMysqlIntegration(t *testing.T) {
 	p.Driver = "mysql"
 	p.DataSourceName = address
 	p.InitSQL = "SET sql_mode='ANSI_QUOTES';"
+	require.NoError(t, p.Init())
 
 	require.NoError(t, p.Connect())
 	require.NoError(t, p.Write(testMetrics))
@@ -282,6 +283,7 @@ func TestPostgresIntegration(t *testing.T) {
 	p.Convert.Real = "double precision"
 	p.Convert.Unsigned = "bigint"
 	p.Convert.ConversionStyle = "literal"
+	require.NoError(t, p.Init())
 
 	require.NoError(t, p.Connect())
 	defer p.Close()
@@ -366,7 +368,6 @@ func TestClickHouseIntegration(t *testing.T) {
 	p.Log = testutil.Logger{}
 	p.Driver = "clickhouse"
 	p.DataSourceName = address
-	p.TableTemplate = "CREATE TABLE {TABLE}({COLUMNS}) ENGINE MergeTree() ORDER by timestamp"
 	p.Convert.Integer = "Int64"
 	p.Convert.Text = "String"
 	p.Convert.Timestamp = "DateTime"
@@ -374,6 +375,7 @@ func TestClickHouseIntegration(t *testing.T) {
 	p.Convert.Unsigned = "UInt64"
 	p.Convert.Bool = "UInt8"
 	p.Convert.ConversionStyle = "literal"
+	require.NoError(t, p.Init())
 
 	require.NoError(t, p.Connect())
 	require.NoError(t, p.Write(testMetrics))

plugins/outputs/sql/sqlite_test.go

@@ -25,6 +25,7 @@ func TestSqlite(t *testing.T) {
 	p.Log = testutil.Logger{}
 	p.Driver = "sqlite"
 	p.DataSourceName = address
+	require.NoError(t, p.Init())
 
 	require.NoError(t, p.Connect())
 	defer p.Close()