fix(spanner): implement common schema collections

Author: alaricd

apis/Google.Cloud.Spanner.Data/Google.Cloud.Spanner.Data.Tests/SpannerConnectionTests.cs

@@ -37,7 +37,10 @@ public void GetSchema_ExposesCommonCollections()
             foreach (var name in new[] { "MetaDataCollections", "DataSourceInformation", "DataTypes", "Restrictions", "ReservedWords" })
             {
                 Assert.Equal(name, connection.GetSchema(name).TableName);
+                Assert.Equal(name, connection.GetSchema(name.ToUpperInvariant()).TableName);
             }
+            var exception = Assert.Throws<ArgumentException>(() => connection.GetSchema("DataTypes", new[] { "restriction" }));
+            Assert.Equal("restrictionValues", exception.ParamName);
         }
 
         [Fact]

apis/Google.Cloud.Spanner.Data/Google.Cloud.Spanner.Data/SpannerConnection.cs

@@ -109,9 +109,13 @@ public override string ConnectionString
         public override DataTable GetSchema(string collectionName, string[] restrictionValues)
         {
             GaxPreconditions.CheckNotNullOrEmpty(collectionName, nameof(collectionName));
-            switch (collectionName)
+            if (restrictionValues != null && restrictionValues.Length != 0)
             {
-                case "MetaDataCollections":
+                throw new ArgumentException("Restrictions are not supported for the requested schema collection.", nameof(restrictionValues));
+            }
+            switch (collectionName.ToUpperInvariant())
+            {
+                case "METADATACOLLECTIONS":
                     var collections = CreateSchemaTable(collectionName,
                         ("CollectionName", typeof(string)),
                         ("NumberOfRestrictions", typeof(int)),
@@ -121,7 +125,7 @@ public override DataTable GetSchema(string collectionName, string[] restrictionV
                         collections.Rows.Add(name, 0, 0);
                     }
                     return collections;
-                case "DataSourceInformation":
+                case "DATASOURCEINFORMATION":
                     return CreateSchemaTable(collectionName,
                         ("CompositeIdentifierSeparatorPattern", typeof(string)),
                         ("DataSourceProductName", typeof(string)),
@@ -139,7 +143,7 @@ public override DataTable GetSchema(string collectionName, string[] restrictionV
                         ("StatementSeparatorPattern", typeof(string)),
                         ("StringLiteralPattern", typeof(string)),
                         ("SupportedJoinOperators", typeof(int)));
-                case "DataTypes":
+                case "DATATYPES":
                     return CreateSchemaTable(collectionName,
                         ("TypeName", typeof(string)), ("ProviderDbType", typeof(int)), ("ColumnSize", typeof(long)),
                         ("CreateFormat", typeof(string)), ("CreateParameters", typeof(string)), ("DataType", typeof(string)),
@@ -149,11 +153,11 @@ public override DataTable GetSchema(string collectionName, string[] restrictionV
                         ("IsUnsigned", typeof(bool)), ("MaximumScale", typeof(short)), ("MinimumScale", typeof(short)),
                         ("IsConcurrencyType", typeof(bool)), ("IsLiteralSupported", typeof(bool)),
                         ("LiteralPrefix", typeof(string)), ("LiteralSuffix", typeof(string)));
-                case "Restrictions":
+                case "RESTRICTIONS":
                     return CreateSchemaTable(collectionName,
                         ("CollectionName", typeof(string)), ("RestrictionName", typeof(string)),
                         ("RestrictionDefault", typeof(string)), ("RestrictionNumber", typeof(int)));
-                case "ReservedWords":
+                case "RESERVEDWORDS":
                     return CreateSchemaTable(collectionName, ("ReservedWord", typeof(string)));
                 default:
                     throw new ArgumentException($"The schema collection '{collectionName}' is not supported.", nameof(collectionName));