[Sqlalchemy-tickets] Issue #4265: support oracle floating point binary precision (zzzeek/sqlalchemy)

[Michael B. <iss...@bi...>]

New issue 4265: support oracle floating point binary precision
https://bitbucket.org/zzzeek/sqlalchemy/issues/4265/support-oracle-floating-point-binary

Michael Bayer:

the Float type supports "precision", however this is taken to mean decimal precision.  Oracle's FLOAT supports a binary precision argument which is totally a different thing: http://www.exploringbinary.com/decimal-precision-of-binary-floating-point-numbers/.       We'd like to support oracle.FLOAT(binary_precision=X) and potentially support conversion of Float(precision) to binary precision, if possible.


```
#!diff


@@ -585,6 +566,9 @@ class OracleTypeCompiler(compiler.GenericTypeCompiler):
     def visit_BINARY_FLOAT(self, type_, **kw):
         return self._generate_numeric(type_, "BINARY_FLOAT", **kw)
 
+    def visit_FLOAT(self, type_, **kw):
+        return self._generate_numeric(type_, "FLOAT", **kw)
+
     def visit_NUMBER(self, type_, **kw):
         return self._generate_numeric(type_, "NUMBER", **kw)
 
@@ -1418,6 +1402,11 @@ class OracleDialect(default.DefaultDialect):
                     coltype = INTEGER()
                 else:
                     coltype = NUMBER(precision, scale)
+            elif coltype == 'FLOAT':
+                if precision is None:
+                    coltype = FLOAT()
+                else:
+                    coltype = FLOAT(precision)
             elif coltype in ('VARCHAR2', 'NVARCHAR2', 'CHAR'):
                 coltype = self.ischema_names.get(coltype)(length)
             elif 'WITH TIME ZONE' in coltype:
```