def p_expr_fromlist_first(t):
'FromList : TCNAME COMMA FromList'
t[1] = common_db.Node('TCNAME', [t[1]])
t[2] = common_db.Node(',', None)
t[0] = common_db.Node('FromList', [t[1], t[2], t[3]])
return t
def p_expr_sellist_second(t):
'SelList : TCNAME'
t[1] = common_db.Node('TCNAME', [t[1]])
t[0] = common_db.Node('SelList', [t[1]])
return t
def p_expr_sellist_first(t):
'SelList : TCNAME COMMA SelList'
t[1] = common_db.Node('TCNAME', [t[1]])
t[2] = common_db.Node(',', None)
t[0] = common_db.Node('SelList', [t[1], t[2], t[3]])
return t
def p_expr_swf(t):
'SFW : SELECT SelList FROM FromList WHERE Cond'
t[1] = common_db.Node('SELECT', None)
t[3] = common_db.Node('FROM', None)
t[5] = common_db.Node('WHERE', None)
t[0] = common_db.Node('SFW', [t[1], t[2], t[3], t[4], t[5], t[6]])
return t
def p_expr_condition(t):
'Cond : TCNAME EQX CONSTANT'
t[1] = common_db.Node('TCNAME', [t[1]])
t[2] = common_db.Node('=', None)
t[3] = common_db.Node('CONSTANT', [t[3]])
t[0] = common_db.Node('Cond', [t[1], t[2], t[3]])
return t
def p_expr_query(t):
'Query : SFW'
t[0] = common_db.Node('Query', [t[1]])
common_db.global_syn_tree = t[0]
check_syn_tree(common_db.global_syn_tree)
common_db.show(common_db.global_syn_tree)
return t
def construct_from_node(from_list):
if from_list:
if len(from_list) == 1:
temp_node = common_db.Node(from_list[0], None)
return common_db.Node('X', [temp_node])
elif len(from_list) == 2:
temp_node_first = common_db.Node(from_list[0], None)
temp_node_second = common_db.Node(from_list[1], None)
return common_db.Node('X', [temp_node_first, temp_node_second])
elif len(from_list) > 2:
right_node = common_db.Node(from_list[len(from_list) - 1], None)
return common_db.Node('X', [
construct_from_node(from_list[0:len(from_list) - 1]),
right_node
])
def construct_select_node(wf_node, sel_list):
if wf_node and len(sel_list) > 0:
return common_db.Node('Proj', [wf_node], sel_list)
def construct_where_node(from_node, where_list):
if from_node and len(where_list) > 0:
return common_db.Node('Filter', [from_node], where_list)
elif from_node and len(where_list) == 0: # there is no where clause
return from_node
def p_expr_fromlist_second(t):
'FromList : TCNAME'
t[1] = common_db.Node('TCNAME', [t[1]])
t[0] = common_db.Node('FromList', [t[1]])
return t