From 27e183a78c8062ed7c2bbb91655a5e56cd697bba Mon Sep 17 00:00:00 2001
From: Cengiz Kaygusuz <cngkaygusuz@gmail.com>
Date: Mon, 20 Nov 2017 20:46:39 -0500
Subject: Move src to root

---
 examples/simpleSQL.py | 88 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 88 insertions(+)
 create mode 100644 examples/simpleSQL.py

(limited to 'examples/simpleSQL.py')

diff --git a/examples/simpleSQL.py b/examples/simpleSQL.py
new file mode 100644
index 0000000..6cde6ce
--- /dev/null
+++ b/examples/simpleSQL.py
@@ -0,0 +1,88 @@
+# simpleSQL.py
+#
+# simple demo of using the parsing library to do simple-minded SQL parsing
+# could be extended to include where clauses etc.
+#
+# Copyright (c) 2003,2016, Paul McGuire
+#
+from pyparsing import Literal, CaselessLiteral, Word, delimitedList, Optional, \
+    Combine, Group, alphas, nums, alphanums, ParseException, Forward, oneOf, quotedString, \
+    ZeroOrMore, restOfLine, CaselessKeyword, pyparsing_common
+
+# define SQL tokens
+selectStmt = Forward()
+SELECT, FROM, WHERE = map(CaselessKeyword, "select from where".split())
+
+ident          = Word( alphas, alphanums + "_$" ).setName("identifier")
+columnName     = delimitedList(ident, ".", combine=True).setName("column name")
+columnName.addParseAction(pyparsing_common.upcaseTokens)
+columnNameList = Group( delimitedList(columnName))
+tableName      = delimitedList(ident, ".", combine=True).setName("table name")
+tableName.addParseAction(pyparsing_common.upcaseTokens)
+tableNameList  = Group(delimitedList(tableName))
+
+whereExpression = Forward()
+and_, or_, in_ = map(CaselessKeyword, "and or in".split())
+
+binop = oneOf("= != < > >= <= eq ne lt le gt ge", caseless=True)
+realNum = pyparsing_common.real()
+intNum = pyparsing_common.signed_integer()
+
+columnRval = realNum | intNum | quotedString | columnName # need to add support for alg expressions
+whereCondition = Group(
+    ( columnName + binop + columnRval ) |
+    ( columnName + in_ + "(" + delimitedList( columnRval ) + ")" ) |
+    ( columnName + in_ + "(" + selectStmt + ")" ) |
+    ( "(" + whereExpression + ")" )
+    )
+whereExpression << whereCondition + ZeroOrMore( ( and_ | or_ ) + whereExpression ) 
+
+# define the grammar
+selectStmt <<= (SELECT + ('*' | columnNameList)("columns") + 
+                FROM + tableNameList( "tables" ) + 
+                Optional(Group(WHERE + whereExpression), "")("where"))
+
+simpleSQL = selectStmt
+
+# define Oracle comment format, and ignore them
+oracleSqlComment = "--" + restOfLine
+simpleSQL.ignore( oracleSqlComment )
+
+if __name__ == "__main__":
+    simpleSQL.runTests("""\
+
+        # multiple tables
+        SELECT * from XYZZY, ABC
+
+        # dotted table name
+        select * from SYS.XYZZY
+
+        Select A from Sys.dual
+
+        Select A,B,C from Sys.dual
+
+        Select A, B, C from Sys.dual, Table2   
+
+        # FAIL - invalid SELECT keyword
+        Xelect A, B, C from Sys.dual
+
+        # FAIL - invalid FROM keyword
+        Select A, B, C frox Sys.dual
+
+        # FAIL - incomplete statement
+        Select
+
+        # FAIL - incomplete statement
+        Select * from
+
+        # FAIL - invalid column
+        Select &&& frox Sys.dual
+
+        # where clause
+        Select A from Sys.dual where a in ('RED','GREEN','BLUE')
+
+        # compound where clause
+        Select A from Sys.dual where a in ('RED','GREEN','BLUE') and b in (10,20,30)
+
+        # where clause with comparison operator
+        Select A,b from table1,table2 where table1.id eq table2.id""")
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