Difference between revisions of "2015 UK General Election using SQL Server"
Line 38: | Line 38: | ||
==Import the csv file into your flat table== | ==Import the csv file into your flat table== | ||
You can import the data using this line | You can import the data using this line | ||
− | + | BULK INSERT ge FROM 'C:\db\ge2015.csv' WITH (FIELDTERMINATOR=',', ROWTERMINATOR='\n', FIRSTROW=2) | |
− | + | GO | |
− | + | *Each line is ended with carriage return \n | |
− | *Each line is ended with | + | *The first row contains column headings not data so we start at row 2 |
− | + | You will most likely get error messages like this: | |
− | + | ||
− | *The first row contains column headings not data | + | Msg 4863, Level 16, State 1, Server ME1C039-130368\SQLEXPRESS, Line 3 |
+ | Bulk load data conversion error (truncation) for row 105, column 13 (sitting_mp). | ||
+ | Msg 4863, Level 16, State 1, Server ME1C039-130368\SQLEXPRESS, Line 3 | ||
+ | Bulk load data conversion error (truncation) for row 106, column 12 (gender). | ||
+ | Msg 4863, Level 16, State 1, Server ME1C039-130368\SQLEXPRESS, Line 3 | ||
+ | Bulk load data conversion error (truncation) for row 107, column 13 (sitting_mp). | ||
+ | ... | ||
+ | |||
+ | ==Identifying the problem rows== | ||
+ | You can look at the data with a text editor or use powershell: | ||
+ | |||
==Run some queries== | ==Run some queries== | ||
Now let's look at some data. | Now let's look at some data. |
Revision as of 13:46, 16 June 2017
This tutorial assumes you have access to powershell and sqlcmd or Microsoft SQL Server Management Studio
Contents
Get to the powershell prompt and download the csv
(new-object system.net.webclient).downloadfile("http://researchbriefings.files.parliament.uk/documents/CBP-7186/hocl-ge2015-results-full.csv","$pwd\e2015.csv")
Go into sqlcmd or SSMS and create a table for the results
Here you create a single flat table that can store all of the unnormalised data.
The first line of the CSV file contains the column headings (ons_id,ons_region_id,constituency_name,county_name,region_name,country_name,constituency_type,party_name,party_abbreviation,firstname,surname,gender,sitting_mp,former_mp,votes,share,change). We create a table with a column for each of these:
sqlcmd -S .\sqlexpress -E
The create table statement could be:
CREATE DATABASE gisq GO USE gisq GO CREATE TABLE ge( ons_id VARCHAR(10), ons_region_id VARCHAR(10), constituency_name VARCHAR(50), county_name VARCHAR(50), region_name VARCHAR(50), country_name VARCHAR(50), constituency_type VARCHAR(10), party_name VARCHAR(50), party_abbreviation VARCHAR(50), firstname VARCHAR(50), surname VARCHAR(50), gender VARCHAR(6), sitting_mp VARCHAR(3), former_mp VARCHAR(3), votes INT, share FLOAT, change VARCHAR(20), PRIMARY KEY(ons_id,firstname,surname) ) GO
Import the csv file into your flat table
You can import the data using this line
BULK INSERT ge FROM 'C:\db\ge2015.csv' WITH (FIELDTERMINATOR=',', ROWTERMINATOR='\n', FIRSTROW=2) GO
- Each line is ended with carriage return \n
- The first row contains column headings not data so we start at row 2
You will most likely get error messages like this:
Msg 4863, Level 16, State 1, Server ME1C039-130368\SQLEXPRESS, Line 3 Bulk load data conversion error (truncation) for row 105, column 13 (sitting_mp). Msg 4863, Level 16, State 1, Server ME1C039-130368\SQLEXPRESS, Line 3 Bulk load data conversion error (truncation) for row 106, column 12 (gender). Msg 4863, Level 16, State 1, Server ME1C039-130368\SQLEXPRESS, Line 3 Bulk load data conversion error (truncation) for row 107, column 13 (sitting_mp). ...
Identifying the problem rows
You can look at the data with a text editor or use powershell:
Run some queries
Now let's look at some data. How many female candidates were there?
select count(1) from ge where gender='female';
Who stood in Edinburgh South?
select surname,votes from ge where constituency_name='Edinburgh South';
You can now move to the next stage: 2015 UK General Election Normalising Data