Cosmos: Add translator for Substring method which map to SUBSTRING bu…

…ilt-in functions (#24284) Cosmos: Add translator for Substring method which map to SUBSTRING built-in function
dotnet · Mar 1, 2021 · 8936a65 · 8936a65
1 parent dea57ad
commit 8936a65
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Showing 3 changed files with 15 additions and 6 deletions.
diff --git a/src/EFCore.Cosmos/Query/Internal/StringMethodTranslator.cs b/src/EFCore.Cosmos/Query/Internal/StringMethodTranslator.cs
@@ -54,6 +54,9 @@ private static readonly MethodInfo _trimEndMethodInfoWithCharArrayArg
         private static readonly MethodInfo _trimMethodInfoWithCharArrayArg
             = typeof(string).GetRequiredRuntimeMethod(nameof(string.Trim), new[] { typeof(char[]) });
 
+        private static readonly MethodInfo _substringMethodInfo
+            = typeof(string).GetRequiredRuntimeMethod(nameof(string.Substring), new[] { typeof(int), typeof(int) });
+
         private static readonly MethodInfo _firstOrDefaultMethodInfoWithoutArgs
             = typeof(Enumerable).GetRuntimeMethods().Single(
                 m => m.Name == nameof(Enumerable.FirstOrDefault)
@@ -155,6 +158,11 @@ public StringMethodTranslator([NotNull] ISqlExpressionFactory sqlExpressionFacto
                 {
                     return TranslateSystemFunction("TRIM", method.ReturnType, instance);
                 }
+
+                if (_substringMethodInfo.Equals(method))
+                {
+                    return TranslateSystemFunction("SUBSTRING", method.ReturnType, instance, arguments[0], arguments[1]);
+                }
             }
 
             if (_firstOrDefaultMethodInfoWithoutArgs.Equals(method))

diff --git a/test/EFCore.Cosmos.FunctionalTests/Query/NorthwindFunctionsQueryCosmosTest.cs b/test/EFCore.Cosmos.FunctionalTests/Query/NorthwindFunctionsQueryCosmosTest.cs
@@ -750,7 +750,7 @@ public override async Task Substring_with_zero_startindex(bool async)
             await base.Substring_with_zero_startindex(async);
 
             AssertSql(
-                @"SELECT c[""ContactName""]
+                @"SELECT SUBSTRING(c[""ContactName""], 0, 3) AS c
 FROM root c
 WHERE ((c[""Discriminator""] = ""Customer"") AND (c[""CustomerID""] = ""ALFKI""))");
         }
@@ -760,7 +760,7 @@ public override async Task Substring_with_zero_length(bool async)
             await base.Substring_with_zero_length(async);
 
             AssertSql(
-                @"SELECT c[""ContactName""]
+                @"SELECT SUBSTRING(c[""ContactName""], 2, 0) AS c
 FROM root c
 WHERE ((c[""Discriminator""] = ""Customer"") AND (c[""CustomerID""] = ""ALFKI""))");
         }
@@ -770,7 +770,7 @@ public override async Task Substring_with_constant(bool async)
             await base.Substring_with_constant(async);
 
             AssertSql(
-                @"SELECT c[""ContactName""]
+                @"SELECT SUBSTRING(c[""ContactName""], 1, 3) AS c
 FROM root c
 WHERE ((c[""Discriminator""] = ""Customer"") AND (c[""CustomerID""] = ""ALFKI""))");
         }
@@ -780,7 +780,9 @@ public override async Task Substring_with_closure(bool async)
             await base.Substring_with_closure(async);
 
             AssertSql(
-                @"SELECT c[""ContactName""]
+                @"@__start_0='2'
+
+SELECT SUBSTRING(c[""ContactName""], @__start_0, 3) AS c
 FROM root c
 WHERE ((c[""Discriminator""] = ""Customer"") AND (c[""CustomerID""] = ""ALFKI""))");
         }

diff --git a/test/EFCore.Cosmos.FunctionalTests/Query/NorthwindWhereQueryCosmosTest.cs b/test/EFCore.Cosmos.FunctionalTests/Query/NorthwindWhereQueryCosmosTest.cs
@@ -1016,15 +1016,14 @@ FROM root c
 WHERE (c[""Discriminator""] = ""Customer"")");
         }
 
-        [ConditionalTheory(Skip = "Issue #17246")]
         public override async Task Where_string_substring(bool async)
         {
             await base.Where_string_substring(async);
 
             AssertSql(
                 @"SELECT c
 FROM root c
-WHERE (c[""Discriminator""] = ""Customer"")");
+WHERE ((c[""Discriminator""] = ""Customer"") AND (SUBSTRING(c[""City""], 1, 2) = ""ea""))");
         }
 
         [ConditionalTheory(Skip = "Issue #17246")]