--- /dev/null
+show databases;
+#create database zipcodes;
+use zipcodes;
+
+describe categories;
+
+select * from categories where image is null;
+
+describe locations;
+
+select * from locations where id > 3000;
+
+# useful floating point compare technique.
+select * from locations where abs(lat - '18.17') <= 1e-6;
+
+select * from locations where id = 607;
+
+select * from locations ;