Move src to root

1 files changed, 126 insertions, 0 deletions

diff --git a/examples/select_parser.py b/examples/select_parser.py
new file mode 100644
index 0000000..f969f02
--- /dev/null
+++ b/examples/select_parser.py
@@ -0,0 +1,126 @@
+# select_parser.py

+# Copyright 2010, Paul McGuire

+#

+# a simple SELECT statement parser, taken from SQLite's SELECT statement

+# definition at http://www.sqlite.org/lang_select.html

+#

+from pyparsing import *

+ParserElement.enablePackrat()

+

+LPAR,RPAR,COMMA = map(Suppress,"(),")

+select_stmt = Forward().setName("select statement")

+

+# keywords

+(UNION, ALL, AND, INTERSECT, EXCEPT, COLLATE, ASC, DESC, ON, USING, NATURAL, INNER, 

+ CROSS, LEFT, OUTER, JOIN, AS, INDEXED, NOT, SELECT, DISTINCT, FROM, WHERE, GROUP, BY,

+ HAVING, ORDER, BY, LIMIT, OFFSET, OR) =  map(CaselessKeyword, """UNION, ALL, AND, INTERSECT, 

+ EXCEPT, COLLATE, ASC, DESC, ON, USING, NATURAL, INNER, CROSS, LEFT, OUTER, JOIN, AS, INDEXED, NOT, SELECT, 

+ DISTINCT, FROM, WHERE, GROUP, BY, HAVING, ORDER, BY, LIMIT, OFFSET, OR""".replace(",","").split())

+(CAST, ISNULL, NOTNULL, NULL, IS, BETWEEN, ELSE, END, CASE, WHEN, THEN, EXISTS,

+ COLLATE, IN, LIKE, GLOB, REGEXP, MATCH, ESCAPE, CURRENT_TIME, CURRENT_DATE, 

+ CURRENT_TIMESTAMP) = map(CaselessKeyword, """CAST, ISNULL, NOTNULL, NULL, IS, BETWEEN, ELSE, 

+ END, CASE, WHEN, THEN, EXISTS, COLLATE, IN, LIKE, GLOB, REGEXP, MATCH, ESCAPE, 

+ CURRENT_TIME, CURRENT_DATE, CURRENT_TIMESTAMP""".replace(",","").split())

+keyword = MatchFirst((UNION, ALL, INTERSECT, EXCEPT, COLLATE, ASC, DESC, ON, USING, NATURAL, INNER, 

+ CROSS, LEFT, OUTER, JOIN, AS, INDEXED, NOT, SELECT, DISTINCT, FROM, WHERE, GROUP, BY,

+ HAVING, ORDER, BY, LIMIT, OFFSET, CAST, ISNULL, NOTNULL, NULL, IS, BETWEEN, ELSE, END, CASE, WHEN, THEN, EXISTS,

+ COLLATE, IN, LIKE, GLOB, REGEXP, MATCH, ESCAPE, CURRENT_TIME, CURRENT_DATE, 

+ CURRENT_TIMESTAMP))

+ 

+identifier = ~keyword + Word(alphas, alphanums+"_")

+collation_name = identifier.copy()

+column_name = identifier.copy()

+column_alias = identifier.copy()

+table_name = identifier.copy()

+table_alias = identifier.copy()

+index_name = identifier.copy()

+function_name = identifier.copy()

+parameter_name = identifier.copy()

+database_name = identifier.copy()

+

+# expression

+expr = Forward().setName("expression")

+

+integer = Regex(r"[+-]?\d+")

+numeric_literal = Regex(r"\d+(\.\d*)?([eE][+-]?\d+)?")

+string_literal = QuotedString("'")

+blob_literal = Regex(r"[xX]'[0-9A-Fa-f]+'")

+literal_value = ( numeric_literal | string_literal | blob_literal |

+    NULL | CURRENT_TIME | CURRENT_DATE | CURRENT_TIMESTAMP )

+bind_parameter = (

+    Word("?",nums) |

+    Combine(oneOf(": @ $") + parameter_name)

+    )

+type_name = oneOf("TEXT REAL INTEGER BLOB NULL")

+

+expr_term = (

+    CAST + LPAR + expr + AS + type_name + RPAR |

+    EXISTS + LPAR + select_stmt + RPAR |

+    function_name.setName("function_name") + LPAR + Optional("*" | delimitedList(expr)) + RPAR |

+    literal_value |

+    bind_parameter |

+    Combine(identifier+('.'+identifier)*(0,2)).setName("ident")

+    )

+

+UNARY,BINARY,TERNARY=1,2,3

+expr << infixNotation(expr_term,

+    [

+    (oneOf('- + ~') | NOT, UNARY, opAssoc.RIGHT),

+    (ISNULL | NOTNULL | NOT + NULL, UNARY, opAssoc.LEFT),

+    ('||', BINARY, opAssoc.LEFT),

+    (oneOf('* / %'), BINARY, opAssoc.LEFT),

+    (oneOf('+ -'), BINARY, opAssoc.LEFT),

+    (oneOf('<< >> & |'), BINARY, opAssoc.LEFT),

+    (oneOf('< <= > >='), BINARY, opAssoc.LEFT),

+    (oneOf('= == != <>') | IS | IN | LIKE | GLOB | MATCH | REGEXP, BINARY, opAssoc.LEFT),

+    ((BETWEEN,AND), TERNARY, opAssoc.LEFT),

+    (IN + LPAR + Group(select_stmt | delimitedList(expr)) + RPAR, UNARY, opAssoc.LEFT),

+    (AND, BINARY, opAssoc.LEFT),

+    (OR, BINARY, opAssoc.LEFT),

+    ])

+

+compound_operator = (UNION + Optional(ALL) | INTERSECT | EXCEPT)

+

+ordering_term = Group(expr('order_key') + Optional(COLLATE + collation_name('collate')) + Optional(ASC | DESC)('direction'))

+

+join_constraint = Group(Optional(ON + expr | USING + LPAR + Group(delimitedList(column_name)) + RPAR))

+

+join_op = COMMA | Group(Optional(NATURAL) + Optional(INNER | CROSS | LEFT + OUTER | LEFT | OUTER) + JOIN)

+

+join_source = Forward()

+single_source = ( (Group(database_name("database") + "." + table_name("table*")) | table_name("table*")) + 

+                    Optional(Optional(AS) + table_alias("table_alias*")) +

+                    Optional(INDEXED + BY + index_name("name") | NOT + INDEXED)("index") | 

+                  (LPAR + select_stmt + RPAR + Optional(Optional(AS) + table_alias)) | 

+                  (LPAR + join_source + RPAR) )

+

+join_source << (Group(single_source + OneOrMore(join_op + single_source + join_constraint)) | 

+                single_source)

+

+result_column = "*" | table_name + "." + "*" | Group(expr + Optional(Optional(AS) + column_alias))

+select_core = (SELECT + Optional(DISTINCT | ALL) + Group(delimitedList(result_column))("columns") +

+                Optional(FROM + join_source("from*")) +

+                Optional(WHERE + expr("where_expr")) +

+                Optional(GROUP + BY + Group(delimitedList(ordering_term)("group_by_terms")) + 

+                        Optional(HAVING + expr("having_expr"))))

+

+select_stmt << (select_core + ZeroOrMore(compound_operator + select_core) +

+                Optional(ORDER + BY + Group(delimitedList(ordering_term))("order_by_terms")) +

+                Optional(LIMIT + (Group(expr + OFFSET + expr) | Group(expr + COMMA + expr) | expr)("limit")))

+

+tests = """\

+    select * from xyzzy where z > 100

+    select * from xyzzy where z > 100 order by zz

+    select * from xyzzy

+    select z.* from xyzzy

+    select a, b from test_table where 1=1 and b='yes'

+    select a, b from test_table where 1=1 and b in (select bb from foo)

+    select z.a, b from test_table where 1=1 and b in (select bb from foo)

+    select z.a, b from test_table where 1=1 and b in (select bb from foo) order by b,c desc,d

+    select z.a, b from test_table left join test2_table where 1=1 and b in (select bb from foo)

+    select a, db.table.b as BBB from db.table where 1=1 and BBB='yes'

+    select a, db.table.b as BBB from test_table,db.table where 1=1 and BBB='yes'

+    select a, db.table.b as BBB from test_table,db.table where 1=1 and BBB='yes' limit 50

+    """

+

+select_stmt.runTests(tests)