first commit

tables/cath_table.py

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+# Таблица с категориями и действия с ними
+
+from dbtable import *
+
+class CathTable(DbTable):
+    def table_name(self):
+        return self.dbconn.prefix + "cath"
+
+    def columns(self):
+        return {"id": ["serial", "PRIMARY KEY"],
+                "cath_name": ["varchar(32)", "NOT NULL"]}
+
+    def table_constraints(self):
+        return ['CONSTRAINT "Name" UNIQUE (cath_name)']
+    
+    
+    def find_by_position(self, num):
+        sql = "SELECT * FROM " + self.table_name()
+        sql += " ORDER BY "
+        sql += ", ".join(self.primary_key())
+        sql += " LIMIT 1 OFFSET %(offset)s"
+        cur = self.dbconn.conn.cursor()
+        cur.execute(sql, {"offset": num - 1})
+        return cur.fetchone()       
+