Broaden is[not]_distinct_from support

Added support for .is[not]_distinct_from to SQL Server, MySQL, and Oracle.

Fixes: #5137
Change-Id: I3b4d3b199821a55687f83c9a5b63a95d07a64cd5

4 files changed, 36 insertions, 3 deletions

diff --git a/lib/sqlalchemy/dialects/mssql/base.py b/lib/sqlalchemy/dialects/mssql/base.py
index 526e6e8ab..69e6834d2 100644
--- a/lib/sqlalchemy/dialects/mssql/base.py
+++ b/lib/sqlalchemy/dialects/mssql/base.py
@@ -1955,6 +1955,18 @@ class MSSQLCompiler(compiler.SQLCompiler):
     def visit_empty_set_expr(self, type_):
         return "SELECT 1 WHERE 1!=1"
 
+    def visit_is_distinct_from_binary(self, binary, operator, **kw):
+        return "NOT EXISTS (SELECT %s INTERSECT SELECT %s)" % (
+            self.process(binary.left),
+            self.process(binary.right),
+        )
+
+    def visit_isnot_distinct_from_binary(self, binary, operator, **kw):
+        return "EXISTS (SELECT %s INTERSECT SELECT %s)" % (
+            self.process(binary.left),
+            self.process(binary.right),
+        )
+
 
 class MSSQLStrictCompiler(MSSQLCompiler):
 
diff --git a/lib/sqlalchemy/dialects/mysql/base.py b/lib/sqlalchemy/dialects/mysql/base.py
index e193c1daa..26d751faa 100644
--- a/lib/sqlalchemy/dialects/mysql/base.py
+++ b/lib/sqlalchemy/dialects/mysql/base.py
@@ -1572,6 +1572,18 @@ class MySQLCompiler(compiler.SQLCompiler):
             }
         )
 
+    def visit_is_distinct_from_binary(self, binary, operator, **kw):
+        return "NOT (%s <=> %s)" % (
+            self.process(binary.left),
+            self.process(binary.right),
+        )
+
+    def visit_isnot_distinct_from_binary(self, binary, operator, **kw):
+        return "%s <=> %s" % (
+            self.process(binary.left),
+            self.process(binary.right),
+        )
+
 
 class MySQLDDLCompiler(compiler.DDLCompiler):
     def get_column_specification(self, column, **kw):
diff --git a/lib/sqlalchemy/dialects/oracle/base.py b/lib/sqlalchemy/dialects/oracle/base.py
index c0ee66ad7..ae869b921 100644
--- a/lib/sqlalchemy/dialects/oracle/base.py
+++ b/lib/sqlalchemy/dialects/oracle/base.py
@@ -1169,6 +1169,18 @@ class OracleCompiler(compiler.SQLCompiler):
 
         return tmp
 
+    def visit_is_distinct_from_binary(self, binary, operator, **kw):
+        return "DECODE(%s, %s, 0, 1) = 1" % (
+            self.process(binary.left),
+            self.process(binary.right),
+        )
+
+    def visit_isnot_distinct_from_binary(self, binary, operator, **kw):
+        return "DECODE(%s, %s, 0, 1) = 0" % (
+            self.process(binary.left),
+            self.process(binary.right),
+        )
+
 
 class OracleDDLCompiler(compiler.DDLCompiler):
     def define_constraint_cascades(self, constraint):
diff --git a/lib/sqlalchemy/dialects/sqlite/base.py b/lib/sqlalchemy/dialects/sqlite/base.py
index 1a13f678f..d3105f268 100644
--- a/lib/sqlalchemy/dialects/sqlite/base.py
+++ b/lib/sqlalchemy/dialects/sqlite/base.py
@@ -1450,9 +1450,6 @@ class SQLiteDialect(default.DefaultDialect):
     colspecs = colspecs
     isolation_level = None
 
-    supports_cast = True
-    supports_default_values = True
-
     construct_arguments = [
         (sa_schema.Table, {"autoincrement": False}),
         (sa_schema.Index, {"where": None}),