Updating column

The following MODIFY clause permanently changes the format for the Population column: World's Largest Countries Name Population ---------------------------------------------------- Brazil 160,310,357 China 1,202,215,077 India 929,009,120 Indonesia 202,393,859 Russia 151,089,979 United States 263,294,808 You might have to change a column's width (and format) before you can update the column.For example, before you can prefix a long text string to Name, you must change the width and format of Name from 35 to 60.First let us start with creating table and populate with sample data to test. TEST ( TEST_ID INT IDENTITY(1,1) NOT NULL, TEST_TEXT TEXT, CONSTRAINT PK_TEST PRIMARY KEY(TEST_ID) ) — File Group clause ; INSERT INTO TEST(TEST_TEXT) VALUES(‘This is test message’); In order to read, write or update TEXT column, we need to first obtain valid pointer to the TEXT column using TEXTPTR command.If query returns more than one row, than value of pointer will be of the last row fetched.A searched update statement depends on the table being updated, all of its conglomerates (units of storage such as heaps or indexes), all of its constraints, and any other table named in the WHERE clause or SET expressions.A CREATE or DROP INDEX statement or an ALTER TABLE statement for the target table of a prepared searched update statement invalidates the prepared searched update statement.If you don’t want to turn the option off, but don’t always want to create calculated columns as you work in a table, you can stop calculated columns from being created automatically.

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If no columns were specified or the select statement did not include a FOR UPDATE clause, all columns may be updated.

In the following example, we will show how we can manipulate such columns.

We will also demonstrate how we can perform similar string manipulation for columns with VARCHAR(MAX) data type introduced in MS SQL Server 2005.

The ADD clause adds a new column to an existing table. You can also specify a length (LENGTH=), format (FORMAT=), informat (INFORMAT=), and a label (LABEL=). To change a column's name, use the RENAME= data set option.

The following ALTER TABLE statement adds the numeric data column Density to the NEWCOUNTRIES table: proc sql; alter table sql.newcountries add density num label='Population Density' format=6.2; title "Population Density Table"; select name format=., capital format=., population format=comma15.0, density from sql.newcountries; Population Density Table Population Name Capital Population Density ------------------------------------------------------------------ Brazil Brasilia 160,310,357 . You cannot change a column's data type by using the MODIFY clause.

Following is the code snippet to read the text column.

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