Added low-level parsing example.

andialbrecht · andialbrecht · commit 3bbc94129d3a · 2009-04-23T08:48:33.000+02:00
diff --git a/examples/column_defs_lowlevel.py b/examples/column_defs_lowlevel.py
@@ -0,0 +1,48 @@
+#!/usr/bin/env python
+
+# Example for retrieving column definitions from a CREATE statement
+# using low-level functions.
+
+import sqlparse
+
+SQL = """CREATE TABLE foo (
+  id integer primary key,
+  title varchar(200) not null,
+  description text
+);"""
+
+
+parsed = sqlparse.parse(SQL)[0]
+
+# extract the parenthesis which holds column definitions
+par = parsed.token_next_by_instance(0, sqlparse.sql.Parenthesis)
+
+
+def extract_definitions(token_list):
+    # assumes that token_list is a parenthesis
+    definitions = []
+    # grab the first token, ignoring whitespace
+    token = token_list.token_next(0)
+    tmp = []
+    while token and not token.match(sqlparse.tokens.Punctuation, ')'):
+        tmp.append(token)
+        idx = token_list.token_index(token)
+        # grab the next token, this times including whitespace
+        token = token_list.token_next(idx, skip_ws=False)
+        # split on ","
+        if (token is not None  # = end of statement
+            and token.match(sqlparse.tokens.Punctuation, ',')):
+            definitions.append(tmp)
+            tmp = []
+            idx = token_list.token_index(token)
+            token = token_list.token_next(idx)
+    if tmp and isinstance(tmp[0], sqlparse.sql.Identifier):
+        definitions.append(tmp)
+    return definitions
+
+
+columns = extract_definitions(par)
+
+for column in columns:
+    print 'NAME: %-12s DEFINITION: %s' % (column[0],
+                                         ''.join(str(t) for t in column[1:]))
