Tests to the IF statement

src/deveeldb-nunit/Deveel.Data.Sql.Expressions/SqlConditionalExpressionTests.cs

@@ -0,0 +1,58 @@
+using System;
+
+using NUnit.Framework;
+
+namespace Deveel.Data.Sql.Expressions {
+	[TestFixture]
+	public static class SqlConditionalExpressionTests {
+		[Test]
+		public static void SimpleCase() {
+			var first = SqlExpression.Constant(34);
+			var second = SqlExpression.Add(SqlExpression.Constant(10), SqlExpression.Constant(24));
+			var condition = SqlExpression.Equal(first, second);
+			var returnExpression = SqlExpression.Constant("It was equal");
+			var conditional = SqlExpression.Conditional(condition, returnExpression);
+
+			var result = conditional.EvaluateToConstant(null, null);
+
+			Assert.IsNotNull(result);
+			Assert.IsFalse(Field.IsNullField(result));
+			Assert.AreEqual("It was equal", result.Value.ToString());
+		}
+
+		[Test]
+		public static void SimpleCaseWithFalse() {
+			var first = SqlExpression.Constant(34);
+			var second = SqlExpression.Add(SqlExpression.Constant(10), SqlExpression.Constant(34));
+			var condition = SqlExpression.Equal(first, second);
+			var ifTrue = SqlExpression.Constant("It was equal");
+			var ifFalse = SqlExpression.Constant("It was not equal");
+
+			var conditional = SqlExpression.Conditional(condition, ifTrue, ifFalse);
+
+			var result = conditional.EvaluateToConstant(null, null);
+
+			Assert.IsNotNull(result);
+			Assert.IsFalse(Field.IsNullField(result));
+			Assert.AreEqual("It was not equal", result.Value.ToString());
+		}
+
+		[Test]
+		public static void CaseNestedFalse() {
+			var first = SqlExpression.Constant(34);
+			var second = SqlExpression.Add(SqlExpression.Constant(10), SqlExpression.Constant(34));
+			var condition = SqlExpression.Equal(first, second);
+			var ifTrue = SqlExpression.Constant("It was equal");
+			var ifFalseReturn = SqlExpression.Constant("It was not equal");
+			var ifFalse = SqlExpression.Conditional(SqlExpression.Constant(true), ifFalseReturn);
+
+			var conditional = SqlExpression.Conditional(condition, ifTrue, ifFalse);
+
+			var result = conditional.EvaluateToConstant(null, null);
+
+			Assert.IsNotNull(result);
+			Assert.IsFalse(Field.IsNullField(result));
+			Assert.AreEqual("It was not equal", result.Value.ToString());
+		}
+	}
+}

src/deveeldb-nunit/Deveel.Data/ConditionalTests.cs

@@ -0,0 +1,40 @@
+using System;
+
+using Deveel.Data.Sql;
+using Deveel.Data.Sql.Expressions;
+using Deveel.Data.Sql.Statements;
+using Deveel.Data.Sql.Types;
+using Deveel.Data.Sql.Variables;
+
+using NUnit.Framework;
+
+namespace Deveel.Data {
+	[TestFixture]
+	public sealed class ConditionalTests : ContextBasedTest {
+		protected override void OnAfterSetup(string testName) {
+			Query.Access().CreateObject(new VariableInfo("a", PrimitiveTypes.Integer(), false) {
+				DefaultExpression = SqlExpression.Constant(34)
+			});
+
+			base.OnAfterSetup(testName);
+		}
+
+		protected override void OnBeforeTearDown(string testName) {
+			Query.Access().DropObject(DbObjectType.Variable, new ObjectName("a"));
+			base.OnBeforeTearDown(testName);
+		}
+
+		[Test]
+		public void SimpleConditional() {
+			var condition = SqlExpression.Equal(SqlExpression.VariableReference("a"), SqlExpression.Constant(34));
+			var ifTrue = new SqlStatement[] {
+				new DeclareVariableStatement("b", PrimitiveTypes.String()),
+				new AssignVariableStatement(SqlExpression.VariableReference("b"), SqlExpression.Constant(21)),  
+			};
+
+			var result = Query.If(condition, ifTrue);
+
+			Assert.IsNotNull(result);
+		}
+	}
+}

src/deveeldb-nunit/deveeldb-nunit.csproj

@@ -135,6 +135,7 @@
     <Compile Include="Deveel.Data.Sql.Compile\SchemaCompileTests.cs" />
     <Compile Include="Deveel.Data.Sql.Compile\SqlCompileTestBase.cs" />
     <Compile Include="Deveel.Data.Sql.Compile\UpdateTests.cs" />
+    <Compile Include="Deveel.Data.Sql.Expressions\SqlConditionalExpressionTests.cs" />
     <Compile Include="Deveel.Data.Sql.Statements\SqlStringFormatTests.cs" />
     <Compile Include="Deveel.Data.Sql.Tables\ColumnTests.cs" />
     <Compile Include="Deveel.Data.Sql.Tables\RowIdTests.cs" />
@@ -149,6 +150,7 @@
     <Compile Include="Deveel.Data\AssignTests.cs" />
     <Compile Include="Deveel.Data\CallTests.cs" />
     <Compile Include="Deveel.Data\CloseTests.cs" />
+    <Compile Include="Deveel.Data\ConditionalTests.cs" />
     <Compile Include="Deveel.Data\ContextBasedTest.cs" />
     <Compile Include="Deveel.Data\ConversionFunctionTests.cs" />
     <Compile Include="Deveel.Data\CreateFunctionTests.cs" />

src/deveeldb/Deveel.Data/RequestExtensions.cs

@@ -521,6 +521,26 @@ public static class RequestExtensions {
 
 		#endregion
 
+		#region If
+
+		public static ITable If(this IRequest request, SqlExpression condition, SqlStatement[] ifTrue) {
+			return If(request, condition, ifTrue, new SqlStatement[0]);
+		}
+
+		public static ITable If(this IRequest request, SqlExpression condition, SqlStatement[] ifTrue, SqlStatement[] ifFalse) {
+			var result = request.ExecuteStatement(new ConditionStatement(condition, ifTrue, ifFalse));
+
+			if (result.Type == StatementResultType.Exception)
+				throw result.Error;
+
+			if (result.Type == StatementResultType.Result)
+				return result.Result;
+
+			throw new NotSupportedException("Cursor-ref in condition not supported (yet).");
+		}
+
+		#endregion
+
 		#endregion
 	}
 }