Tutorial by Examples: column

SQLite uses dynamic typing and ignores declared column types: > CREATE TABLE Test ( Col1 INTEGER, Col2 VARCHAR(2), -- length is ignored, too Col3 BLOB, Col4, -- no type required Col5 FLUFFY BUNNIES -- use whatever you want ); > ...

Given a DataFrame with MultiIndex columns # build an example DataFrame midx = pd.MultiIndex(levels=[['zero', 'one'], ['x','y']], labels=[[1,1,0,],[1,0,1,]]) df = pd.DataFrame(np.random.randn(2,3), columns=midx) In [2]: df Out[2]: one zero y x ...

Start with a standard DataFrame df = pd.DataFrame(np.random.randn(2,3), columns=['a','b','c']) In [91]: df Out[91]: a b c 0 -0.911752 -1.405419 -0.978419 1 0.603888 -1.187064 -0.035883 Now to change to MultiIndex, create a MultiIndex object and assign it to df....

MultiIndex can also be used to create DataFrames with multilevel columns. Just use the columns keyword in the DataFrame command. midx = pd.MultiIndex(levels=[['zero', 'one'], ['x','y']], labels=[[1,1,0,],[1,0,1,]]) df = pd.DataFrame(np.random.randn(6,4), columns=midx) In [86]: df Out[86]: ...

CREATE TYPE dbo.Ids as TABLE ( Id int PRIMARY KEY )

CREATE TYPE MyComplexType as TABLE ( Id int, Name varchar(10) )

CREATE TYPE MyUniqueNamesType as TABLE ( FirstName varchar(10), LastName varchar(10), CreateDate datetime default GETDATE() PRIMARY KEY (FirstName,LastName) )

Renaming a column can be done in a single statement but as well as the new name, the "column definition" (i.e. its data type and other optional properties such as nullability, auto incrementing etc.) must also be specified. ALTER TABLE `<table name>` CHANGE `<old name>` `<n...

A computed column is computed from an expression that can use other columns in the same table. The expression can be a noncomputed column name, constant, function, and any combination of these connected by one or more operators. Create table with a computed column Create table NetProfit ( Sa...

Suppose you have a DataFrame of numerical values, for example: df = pd.DataFrame(np.random.randn(1000, 3), columns=['a', 'b', 'c']) Then >>> df.corr() a b c a 1.000000 0.018602 0.038098 b 0.018602 1.000000 -0.014245 c 0.038098 -0.014245 1.000000...

Private Sub Get_Last_Used_Row_Index() Dim wS As Worksheet Set wS = ThisWorkbook.Sheets("Sheet1") Debug.Print LastCol_1(wS) Debug.Print LastCol_0(wS) End Sub You can choose between 2 options, regarding if you want to know if there is no data in the worksheet :...

If you want to have a table organized in column-store format instead of row store, add INDEX cci CLUSTERED COLUMNSTORE in definition of table: DROP TABLE IF EXISTS Product GO CREATE TABLE Product ( ProductID int, Name nvarchar(50) NOT NULL, Color nvarchar(15), Size nvarchar(5)...

CREATE CLUSTERED COLUMNSTORE INDEX enables you to organize a table in column format: DROP TABLE IF EXISTS Product GO CREATE TABLE Product ( Name nvarchar(50) NOT NULL, Color nvarchar(15), Size nvarchar(5) NULL, Price money NOT NULL, Quantity int ) GO CREATE CLUSTERED C...

Suppose that we have the following text file: jekyll_hyde.txt How do we convert it to a PDF that looks like this: When using iText 5, you'd need code like this: public void createPdf(String dest) throws DocumentException, IOException { Document document = new Document(); PdfWriter wr...

Suppose that you have the following text file: jekyll_hyde.txt How do we convert it to a PDF that looks like this: When using iText 7, you'd need code like this: public void createPdf(String dest) throws IOException { PdfDocument pdf = new PdfDocument(new PdfWriter(dest)); Document do...

In MySQL and other SQL dialects, NULL values have special properties. Consider the following table containing job applicants, the companies they worked for, and the date they left the company. NULL indicates that an applicant still works at the company: CREATE TABLE example (`applicant_id` INT, `...

/* The result can be use for fast way to use columns on Insertion/Updates. Works with tables and views. Example: eTableColumns 'Customers' ColumnNames ------------------------------------------------------ Id, FName, LName, Email, PhoneNumber, PreferredContact INSERT INTO Customers (Id, ...

These classes increase the left margin of a column by * columns. For example, .col-md-offset-4 moves .col-md-4 over four columns. <div class="row"> <div class="col-lg-4"></div> <div class="col-lg-4 col-lg-offset-4"></div> </div&g...

If more than 12 columns are placed within a single row, each group of extra columns will, as one unit, wrap onto a new line. <div class="row"> <div class="col-xs-9">.col-xs-9</div> <div class="col-xs-4">.col-xs-4<br>Since 9 + 4 = 13 ...

With the four tiers of grids available you're bound to run into issues where, at certain breakpoints, your columns don't clear quite right as one is taller than the other. To fix that, use a combination of a .clearfix and our responsive utility classes. <div class="row"> <div ...