SAS 9.4 SQL Procedure User's Guide, Fourth Edition, 4th Edition

Glossary

calculated column

a column that does not exist in any of the tables that are accessed, but which is

created as a result of a column expression. See also column expression.

Cartesian product

a type of join that matches each row from each joined table to each row from all

other joined tables. See also cross join, join.

column

a vertical component of a table. Each column has a unique name, contains data of a

specific type, and has particular attributes. A column is analogous to a variable in

SAS terminology.

column alias

a temporary, alternate name for a column. Aliases can be specified in the SQL

procedure's SELECT clause to name or rename columns. An alias is one word. See

also column.

column expression

a set of operators and operands that, when evaluated, result in a single data value.

The resulting data value can be either a character value or a numeric value.

composite index

an index that locates observations in a SAS data set by examining the values of two

or more key variables. See also simple index.

conditional operator

in the SQL procedure, the part of the WHERE clause that specifies which rows are to

be retrieved.

cross join

a type of join that returns the product of joined tables. A cross join is functionally the

same as a Cartesian product. See also Cartesian product, join.

data set

See SAS data set.

data view

See SAS data view.

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DISTINCT

a keyword that causes the SQL procedure to remove duplicate rows from the output.

equijoin

a type of join in the SQL procedure. For example, when two tables are joined in an

equijoin, the value of a column in the first table must equal the value of the column

in the second table in the SQL expression. See also join.

format

See SAS format.

group

a set of rows or observations that have the same value or values for one or more

common columns or variables.

in-line view

a query expression that is nested in the SQL procedure's FROM clause. An in-line

view produces a table internally that the outer query uses to select data. You save a

programming step when you use an in-line view, because instead of creating a view

and then referring to it in another query, you can specify the view in-line in the

FROM clause. An in-line view can be referenced only in the query (or statement) in

which it is defined.

index

See SAS index.

inner join

a join between two tables that returns all of the rows in one table that have one or

more matching rows in the other table.

integrity constraint

a data validation rule that restricts the data values that can be stored for a variable in

a SAS data file. Integrity constraints help preserve the validity and consistency of the

data.

join

an operation that combines data from two or more tables. A join is typically created

by means of SQL (Structured Query Language) code or a user interface. See also

outer join.

join criteria

the set of parameters that determine how tables are to be joined. Join criteria are

usually specified in a WHERE expression or in an SQL ON clause. See also join,

outer join.

missing value

a type of value for a variable that contains no data for a particular row or column. By

default, SAS writes a missing numeric value as a single period and a missing

character value as a blank space.

natural join

a type of join that returns selected rows from tables in which one or more columns in

each table have the same name and the same data type and contain the same value.

See also join.

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