Merge pull request #1036 from ClickHouse/docs/low-cardinality

docs: add LowCardinality(String) example
ClickHouse · Jan 31, 2025 · 22981da · 22981da
2 parents 3f22486 + 2272241
commit 22981da
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Showing 2 changed files with 17 additions and 6 deletions.
diff --git a/README.md b/README.md
@@ -96,6 +96,7 @@ CREATE TABLE test_table_insert
     ts                DateTime64(9),
     severity_text     Enum8('INFO'=1, 'DEBUG'=2),
     severity_number   UInt8,
+    service_name      LowCardinality(String),
     body              String,
     name              String,
     arr               Array(String)
@@ -111,9 +112,11 @@ var (
 	sevText   proto.ColEnum
 	sevNumber proto.ColUInt8
 
-	ts  = new(proto.ColDateTime64).WithPrecision(proto.PrecisionNano) // DateTime64(9)
-	arr = new(proto.ColStr).Array()                                   // Array(String)
-	now = time.Date(2010, 1, 1, 10, 22, 33, 345678, time.UTC)
+    // or new(proto.ColStr).LowCardinality()
+    serviceName = proto.NewLowCardinality(new(proto.ColStr))
+    ts          = new(proto.ColDateTime64).WithPrecision(proto.PrecisionNano) // DateTime64(9)
+    arr         = new(proto.ColStr).Array()                                   // Array(String)
+    now         = time.Date(2010, 1, 1, 10, 22, 33, 345678, time.UTC)
 )
 
 // Append 10 rows to initial data block.
@@ -124,6 +127,7 @@ for i := 0; i < 10; i++ {
 	sevText.Append("INFO")
 	sevNumber.Append(10)
 	arr.Append([]string{"foo", "bar", "baz"})
+    serviceName.Append("service")
 }
 
 input := proto.Input{
@@ -186,6 +190,7 @@ if err := conn.Do(ctx, ch.Query{
 			sevText.Append("DEBUG")
 			sevNumber.Append(10)
 			arr.Append([]string{"foo", "bar", "baz"})
+            serviceName.Append("service")
 		}
 
 		// Data will be encoded and sent to ClickHouse server after returning nil.

diff --git a/examples/insert/main.go b/examples/insert/main.go
@@ -23,6 +23,7 @@ func main() {
     ts                DateTime64(9),
     severity_text     Enum8('INFO'=1, 'DEBUG'=2),
     severity_number   UInt8,
+	service_name      LowCardinality(String),
     body              String,
     name              String,
     arr               Array(String)
@@ -38,9 +39,11 @@ func main() {
 		sevText   proto.ColEnum
 		sevNumber proto.ColUInt8
 
-		ts  = new(proto.ColDateTime64).WithPrecision(proto.PrecisionNano) // DateTime64(9)
-		arr = new(proto.ColStr).Array()                                   // Array(String)
-		now = time.Date(2010, 1, 1, 10, 22, 33, 345678, time.UTC)
+		// or new(proto.ColStr).LowCardinality()
+		serviceName = proto.NewLowCardinality(new(proto.ColStr))
+		ts          = new(proto.ColDateTime64).WithPrecision(proto.PrecisionNano) // DateTime64(9)
+		arr         = new(proto.ColStr).Array()                                   // Array(String)
+		now         = time.Date(2010, 1, 1, 10, 22, 33, 345678, time.UTC)
 	)
 
 	// Append 10 rows to initial data block.
@@ -51,13 +54,15 @@ func main() {
 		sevText.Append("INFO")
 		sevNumber.Append(10)
 		arr.Append([]string{"foo", "bar", "baz"})
+		serviceName.Append("service")
 	}
 
 	// Insert single data block.
 	input := proto.Input{
 		{Name: "ts", Data: ts},
 		{Name: "severity_text", Data: &sevText},
 		{Name: "severity_number", Data: &sevNumber},
+		{Name: "service_name", Data: serviceName},
 		{Name: "body", Data: &body},
 		{Name: "name", Data: &name},
 		{Name: "arr", Data: arr},
@@ -106,6 +111,7 @@ func main() {
 				sevText.Append("DEBUG")
 				sevNumber.Append(10)
 				arr.Append([]string{"foo", "bar", "baz"})
+				serviceName.Append("service")
 			}
 
 			// Data will be encoded and sent to ClickHouse server after returning nil.