Add SqlFilter to typed SqlExpressions

Author: mythz

src/ServiceStack.OrmLite/Expressions/SqlExpression.cs

@@ -43,6 +43,7 @@ public abstract partial class SqlExpression<T> : ISqlExpression, IHasUntypedSqlE
         public bool WhereStatementWithoutWhereString { get; set; }
         public IOrmLiteDialectProvider DialectProvider { get; set; }
         public List<IDbDataParameter> Params { get; set; }
+        public Func<string,string> SqlFilter { get; set; }
 
         protected string Sep => sep;
 
@@ -84,6 +85,7 @@ protected virtual SqlExpression<T> CopyTo(SqlExpression<T> to)
             to.PrefixFieldWithTableName = PrefixFieldWithTableName;
             to.WhereStatementWithoutWhereString = WhereStatementWithoutWhereString;
             to.Params = new List<IDbDataParameter>(Params);
+            to.SqlFilter = SqlFilter;
             return to;
         }
 
@@ -939,6 +941,12 @@ public virtual SqlExpression<T> Insert()
             return this;
         }
 
+        public virtual SqlExpression<T> WithSqlFilter(Func<string,string> sqlFilter)
+        {
+            this.SqlFilter = sqlFilter;
+            return this;
+        }
+
         public string SqlTable(ModelDefinition modelDef)
         {
             return DialectProvider.GetQuotedTableName(modelDef);
@@ -988,17 +996,24 @@ public virtual void CopyParamsTo(IDbCommand dbCmd)
 
         public virtual string ToDeleteRowStatement()
         {
+            string sql;
             var hasTableJoin = tableDefs.Count > 1;
             if (hasTableJoin)
             {
                 var clone = this.Clone();
                 var pk = DialectProvider.GetQuotedColumnName(modelDef, modelDef.PrimaryKey);
                 clone.Select(pk);
                 var subSql = clone.ToSelectStatement();
-                var sql = $"DELETE FROM {DialectProvider.GetQuotedTableName(modelDef)} WHERE {pk} IN ({subSql})";
-                return sql;
+                sql = $"DELETE FROM {DialectProvider.GetQuotedTableName(modelDef)} WHERE {pk} IN ({subSql})";
+            }
+            else
+            {
+                sql = $"DELETE FROM {DialectProvider.GetQuotedTableName(modelDef)} {WhereExpression}";
             }
-            return $"DELETE FROM {DialectProvider.GetQuotedTableName(modelDef)} {WhereExpression}";
+
+            return SqlFilter != null
+                ? SqlFilter(sql)
+                : sql;
         }
 
         public virtual void PrepareUpdateStatement(IDbCommand dbCmd, T item, bool excludeDefaults = false)
@@ -1031,21 +1046,31 @@ public virtual void PrepareUpdateStatement(IDbCommand dbCmd, T item, bool exclud
             if (setFields.Length == 0)
                 throw new ArgumentException("No non-null or non-default values were provided for type: " + typeof(T).Name);
 
-            dbCmd.CommandText = $"UPDATE {DialectProvider.GetQuotedTableName(modelDef)} " +
-                                $"SET {StringBuilderCache.ReturnAndFree(setFields)} {WhereExpression}";
+            var sql = $"UPDATE {DialectProvider.GetQuotedTableName(modelDef)} " +
+                      $"SET {StringBuilderCache.ReturnAndFree(setFields)} {WhereExpression}";
+
+            dbCmd.CommandText = SqlFilter != null
+                ? SqlFilter(sql)
+                : sql;
         }
 
         public virtual string ToSelectStatement()
         {
             var sql = DialectProvider
                 .ToSelectStatement(modelDef, SelectExpression, BodyExpression, OrderByExpression, Offset, Rows);
 
-            return sql;
+            return SqlFilter != null
+                ? SqlFilter(sql)
+                : sql;
         }
 
         public virtual string ToCountStatement()
         {
-            return "SELECT COUNT(*)" + BodyExpression;
+            var sql = "SELECT COUNT(*)" + BodyExpression;
+
+            return SqlFilter != null
+                ? SqlFilter(sql)
+                : sql;
         }
 
         public string SelectExpression

tests/ServiceStack.OrmLite.Tests/Expression/SqlExpressionFilterTests.cs

@@ -0,0 +1,31 @@
+using NUnit.Framework;
+using ServiceStack.OrmLite.Tests.Shared;
+using ServiceStack.Text;
+
+namespace ServiceStack.OrmLite.Tests.Expression
+{
+    public class SqlExpressionFilterTests : OrmLiteTestBase
+    {
+        [Test]
+        public void Can_enhance_SqlExpression_with_Custom_SqlFilter()
+        {
+            if (Dialect != Dialect.SqlServer) return;
+
+            using (var db = OpenDbConnection())
+            {
+                db.DropAndCreateTable<Person>();
+
+                db.InsertAll(Person.Rockstars);
+
+                var q = db.From<Person>()
+                    .Where(x => x.Age == 27)
+                    .WithSqlFilter(sql => sql + "\noption (recompile)");
+
+                var rockstars = db.Select(q);
+                Assert.That(rockstars.Count, Is.EqualTo(4));
+
+                Assert.That(db.GetLastSql(), Does.Contain("option (recompile)"));
+            }
+        }
+    }
+}

tests/ServiceStack.OrmLite.Tests/ServiceStack.OrmLite.Tests.csproj

@@ -139,6 +139,7 @@
     <Compile Include="Expression\JoinAliasTests.cs" />
     <Compile Include="Expression\RestrictionTests.cs" />
     <Compile Include="Expression\SqlExpressionDeleteTests.cs" />
+    <Compile Include="Expression\SqlExpressionFilterTests.cs" />
     <Compile Include="Expression\SqlExpressionJoinTests.cs" />
     <Compile Include="Issues\JoinAliasWithSchemaIssue.cs" />
     <Compile Include="Issues\JsonUpdateOnlyIssue.cs" />