Add support for CASE operator.

sqlbuilder/func_expression_test.go

@@ -0,0 +1,33 @@
+package sqlbuilder
+
+import (
+	"gotest.tools/assert"
+	"testing"
+)
+
+func TestCase1(t *testing.T) {
+	query := CASE().
+		WHEN(table3Col1.EqL(1)).THEN(table3Col1.Add(IntLiteral(1))).
+		WHEN(table3Col1.EqL(2)).THEN(table3Col1.Add(IntLiteral(2)))
+
+	queryData := &queryData{}
+
+	err := query.Serialize(queryData)
+
+	assert.NilError(t, err)
+	assert.Equal(t, queryData.buff.String(), `(CASE WHEN table3.col1 = $1 THEN table3.col1 + $2 WHEN table3.col1 = $3 THEN table3.col1 + $4 END)`)
+}
+
+func TestCase2(t *testing.T) {
+	query := CASE(table3Col1).
+		WHEN(IntLiteral(1)).THEN(table3Col1.Add(IntLiteral(1))).
+		WHEN(IntLiteral(2)).THEN(table3Col1.Add(IntLiteral(2))).
+		ELSE(IntLiteral(0))
+
+	queryData := &queryData{}
+
+	err := query.Serialize(queryData)
+
+	assert.NilError(t, err)
+	assert.Equal(t, queryData.buff.String(), `(CASE table3.col1 WHEN $1 THEN table3.col1 + $2 WHEN $3 THEN table3.col1 + $4 ELSE $5 END)`)
+}