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1 Chapter 2 Basic SQL SELECT Statements
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2 Chapter Objectives Distinguish between an RDBMS and an ORDBMS Identify keywords, mandatory clauses, and optional clauses in a SELECT statement Select and view all columns of a table Select and view one column of a table
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3 Chapter Objectives Display multiple columns of a table Use a column alias to clarify the contents of a particular column Perform basic arithmetic operations in the SELECT clause
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4 Chapter Objectives Remove duplicate lists, using either the DISTINCT or UNIQUE keyword Combine fields, literals, and other data Format output
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5 Relational Database Management System (RDBMS) An RDBMS is the software program used to create the database and it allows you to enter, manipulate, and retrieve data
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6 Object Relational Database Management System (ORDBMS) Same as an RDBMS except it can be used to reference objects such as maps and object fields
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7 SELECT Statement Syntax SELECT statements are used to retrieve data from the database Syntax gives the basic structure, or rules, for a command
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8 SELECT Statement Syntax Optional clauses and keywords are shown in brackets
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9 SELECT Statement Syntax SELECT and FROM clauses are required SELECT clause identifies column(s) FROM clause identifies table(s) Each clause begins with a keyword
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10 Selecting All Data in a Table Substitute an asterisk for the column names in a SELECT clause
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11 Selecting One Column from a Table Enter column name in SELECT clause
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12 Selecting Multiple Columns from a Table Separate column names with a comma
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13 Operations Within the SELECT Statement Column alias can be used for column headings Perform arithmetic operations Suppress duplicates Concatenate data
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14 Column Alias List after column heading AS keyword is optional Enclose in double quotation marks: –If it contains blank space(s) –If it contains special symbol(s) –To retain case
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15 Column Alias Example
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16 Arithmetic Operations Executed left to right Multiplication and division are solved first Addition and subtraction are solved last Override order with parentheses
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17 Example Arithmetic Operation with Column Alias
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18 Suppressing Duplicates Enter DISTINCT or UNIQUE after SELECT keyword
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19 Concatenation Can combine data with string literal Use concatenation operator, || Allows use of column alias
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20 Concatenation Example
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