add tests on rows.ColumnTypes

Author: Sergei Sobolev

clickhouse_decimal_test.go

@@ -0,0 +1,102 @@
+package clickhouse_test
+
+import (
+	"database/sql"
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func Test_Decimal(t *testing.T) {
+	const (
+		ddl = `
+			CREATE TABLE clickhouse_test_nullable (
+				decimal  Decimal(18,5),
+				decimalNullable  Nullable(Decimal(15,3))
+			) Engine=Memory;
+		`
+		dml = `
+			INSERT INTO clickhouse_test_nullable (
+				decimal,
+				decimalNullable
+			) VALUES (
+				?,
+				?
+			)
+		`
+		query = `
+			SELECT
+				decimal,
+				decimalNullable
+			FROM clickhouse_test_nullable
+		`
+	)
+	if connect, err := sql.Open("clickhouse", "tcp://127.0.0.1:9000?debug=true"); assert.NoError(t, err) {
+		if tx, err := connect.Begin(); assert.NoError(t, err) {
+			if _, err := connect.Exec("DROP TABLE IF EXISTS clickhouse_test_nullable"); assert.NoError(t, err) {
+				if _, err := tx.Exec(ddl); assert.NoError(t, err) {
+					if tx, err := connect.Begin(); assert.NoError(t, err) {
+						if stmt, err := tx.Prepare(dml); assert.NoError(t, err) {
+							for i := 0; i < 10; i++ {
+								if _, err := stmt.Exec(
+									16.55,
+									nil,
+								); !assert.NoError(t, err) {
+									t.Fatal(err)
+								}
+							}
+						}
+						if err := tx.Commit(); !assert.NoError(t, err) {
+							t.Fatal(err)
+						}
+					}
+					if rows, err := connect.Query(query); assert.NoError(t, err) {
+						columnTypes, err := rows.ColumnTypes()
+						assert.NoError(t, err)
+						for i, column := range columnTypes {
+							switch i {
+							case 0:
+								nullable, nullableOk := column.Nullable()
+								assert.False(t, nullable)
+								assert.True(t, nullableOk)
+
+								precision, scale, ok := column.DecimalSize()
+								assert.Equal(t, int64(5), scale)
+								assert.Equal(t, int64(18), precision)
+								assert.True(t, ok)
+							case 1:
+								nullable, nullableOk := column.Nullable()
+								assert.True(t, nullable)
+								assert.True(t, nullableOk)
+
+								precision, scale, ok := column.DecimalSize()
+								assert.Equal(t, int64(3), scale)
+								assert.Equal(t, int64(15), precision)
+								assert.True(t, ok)
+							}
+						}
+						for rows.Next() {
+							var (
+								decimal         = new(int)
+								decimalNullable = new(int)
+							)
+							if err := rows.Scan(
+								&decimal,
+								&decimalNullable,
+							); assert.NoError(t, err) {
+								if assert.NotNil(t, decimal) {
+									assert.Equal(t, int(1655000), *decimal)
+								}
+								assert.Nil(t, decimalNullable)
+
+								//t.Log(
+								//	*decimal,
+								//	*decimalNullable,
+								//)
+							}
+						}
+					}
+				}
+			}
+		}
+	}
+}