Implement sum aggregation for decimal in SQLite

Contributes to dotnet#19635
ranma42 · May 15, 2024 · 807740a · 807740a
1 parent 5ffdda0
commit 807740a
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Showing 3 changed files with 41 additions and 3 deletions.
diff --git a/src/EFCore.Sqlite.Core/Query/Internal/SqliteQueryableAggregateMethodTranslator.cs b/src/EFCore.Sqlite.Core/Query/Internal/SqliteQueryableAggregateMethodTranslator.cs
@@ -1,4 +1,4 @@
-// Licensed to the .NET Foundation under one or more agreements.
+// Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using Microsoft.EntityFrameworkCore.Query.SqlExpressions;
@@ -99,8 +99,14 @@ public SqliteQueryableAggregateMethodTranslator(ISqlExpressionFactory sqlExpress
                     var sumArgumentType = GetProviderType(sumSqlExpression);
                     if (sumArgumentType == typeof(decimal))
                     {
-                        throw new NotSupportedException(
-                            SqliteStrings.AggregateOperationNotSupported(nameof(Queryable.Sum), sumArgumentType.ShortDisplayName()));
+                        sumSqlExpression = CombineTerms(source, sumSqlExpression);
+                        return _sqlExpressionFactory.Function(
+                            "ef_sum",
+                            [sumSqlExpression],
+                            nullable: true,
+                            argumentsPropagateNullability: [false],
+                            sumSqlExpression.Type,
+                            sumSqlExpression.TypeMapping);
                     }
 
                     break;

diff --git a/src/EFCore.Sqlite.Core/Query/Internal/SqliteSqlNullabilityProcessor.cs b/src/EFCore.Sqlite.Core/Query/Internal/SqliteSqlNullabilityProcessor.cs
@@ -85,6 +85,30 @@ protected virtual SqlExpression VisitRegexp(
         return regexpExpression.Update(match, pattern);
     }
 
+    /// <inheritdoc/>
+    protected override SqlExpression VisitSqlFunction(
+        SqlFunctionExpression sqlFunctionExpression,
+        bool allowOptimizedExpansion,
+        out bool nullable)
+    {
+        var result = base.VisitSqlFunction(sqlFunctionExpression, allowOptimizedExpansion, out nullable);
+
+        if (result is SqlFunctionExpression resultFunctionExpression
+            && resultFunctionExpression.IsBuiltIn
+            && string.Equals(resultFunctionExpression.Name, "ef_sum", StringComparison.OrdinalIgnoreCase))
+        {
+            nullable = false;
+
+            var sqlExpressionFactory = Dependencies.SqlExpressionFactory;
+            return sqlExpressionFactory.Coalesce(
+                result,
+                sqlExpressionFactory.Constant(0, resultFunctionExpression.TypeMapping),
+                resultFunctionExpression.TypeMapping);
+        }
+
+        return result;
+    }
+
 #pragma warning disable EF1001
     /// <summary>
     ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to

diff --git a/src/EFCore.Sqlite.Core/Storage/Internal/SqliteRelationalConnection.cs b/src/EFCore.Sqlite.Core/Storage/Internal/SqliteRelationalConnection.cs
@@ -142,6 +142,14 @@ private void InitializeDbConnection(DbConnection connection)
                 name: "ef_negate",
                 (decimal? m) => -m,
                 isDeterministic: true);
+
+            sqliteConnection.CreateAggregate(
+                "ef_sum",
+                seed: null,
+                (decimal? sum, decimal? value) => value is null
+                    ? sum
+                    : sum is null ? value : sum.Value + value.Value,
+                isDeterministic: true);
         }
         else
         {