📄 namingconventions.htm
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<span style="font-family:Helvetica,Arial; font-size:12pt; color:#000000"><b>Naming Conventions
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Absolute Database requires to apply the following rules and naming conventions to all SQL statements.
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<b>Database File Names
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</b>Absolute DB supports specifying a database file name in SQL statement. The main reason for specifying a database file name in a query is a selecting table records from multiple databases by a single query.
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In all other cases you don't need to specify database file name within a SQL statement.
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The database file name must be enclosed in double quotes (""):
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<table width="100%" border="0" cellpadding="0" cellspacing="0"><tr valign="top"><td width="14"></td><td><span style="font-family:Helvetica,Arial; font-size:4pt; color:#000000"></span></span><span style="font-family:Courier New; font-size:8pt; color:#000000"><b>SELECT</b> * <b>FROM</b> "c:\data\parts_db.abs".parts, "c:\data\orders_db.abs".orders
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<b>Table Names
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</b>Absolute DB supports not only ANSI SQL identifiers, but it is advanced to support multi-word and national table names. A <i>reserved word</i> could also be used as a table name. In such specific cases the table name must be enclosed in single quotes, double quotes, or square brackets.
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The following example illustrates using of standard identifier as a table name:
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<table width="100%" border="0" cellpadding="0" cellspacing="0"><tr valign="top"><td width="14"></td><td><span style="font-family:Helvetica,Arial; font-size:4pt; color:#000000"></span></span><span style="font-family:Courier New; font-size:8pt; color:#000000"><b>SELECT</b> * <b>FROM</b> Employee</span><span style="font-family:Helvetica,Arial; font-size:10pt; color:#000000"><b>
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</b></span></td></tr></table><table width="100%" border="0" cellpadding="0" cellspacing="0"><tr valign="top"><td width="14"></td><td><span style="font-family:Helvetica,Arial; font-size:10pt; color:#000000"><b></b></span></td></tr></table><span style="font-family:Helvetica,Arial; font-size:10pt; color:#000000"><b>
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</b>The next statement shows how to use multi-word table name:
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<table width="100%" border="0" cellpadding="0" cellspacing="0"><tr valign="top"><td width="14"></td><td><span style="font-family:Helvetica,Arial; font-size:4pt; color:#000000"></span></span><span style="font-family:Courier New; font-size:8pt; color:#000000"><b>SELECT</b> * <b>FROM</b> "Our Employees"
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</span><span style="font-family:Helvetica,Arial; font-size:10pt; color:#000000"><b>Column Names
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</b>Absolute DB supports not only ANSI SQL identifiers, but it is advanced to support multi-word and national column names. A <i><a href=reservedwords.htm>reserved word</a></i> could also be used as a column name. In such specific cases the column name must be enclosed in square brackets:
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</span><span style="font-family:Courier New; font-size:4pt; color:#000000"><b>
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</b><table width="100%" border="0" cellpadding="0" cellspacing="0"><tr valign="top"><td width="14"></td><td><span style="font-family:Courier New; font-size:4pt; color:#000000"></span></span><span style="font-family:Courier New; font-size:8pt; color:#000000"><b>SELECT</b> [First Name] <b>FROM</b> Students
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<b>Correlation Names</b>
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To simplify SQL statement table and column correlation names are often used (AS keyword is optional):
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<table width="100%" border="0" cellpadding="0" cellspacing="0"><tr valign="top"><td width="14"></td><td><span style="font-family:Helvetica,Arial; font-size:4pt; color:#000000"></span></span><span style="font-family:Courier New; font-size:8pt; color:#000000"><b>SELECT</b> E.EmpNo <b>AS</b> No <b>FROM</b> Employee E
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<b>Constants
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</b>Absolute DB supports string, number, boolean, currency, date, and time constants.
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The string, date and time constants must be enclosed in single or double quotes.
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To insert a single quote into a column, use two consecutive single quotation marks.
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For example, to insert the characters "a'b" into col1, use:
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<table width="100%" border="0" cellpadding="0" cellspacing="0"><tr valign="top"><td width="14"></td><td><span style="font-family:Helvetica,Arial; font-size:4pt; color:#000000"></span></span><span style="font-family:Courier New; font-size:8pt; color:#000000"><b>INSERT</b> <b>INTO</b> Orders (col1) <b>VALUES</b>('a''b')
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</span><span style="font-family:Helvetica,Arial; font-size:10pt; color:#000000"><b>Comments
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</b>Absolute Database supports single-line and multi-line comments which you can use to embed some remarks into SQL statement.
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Single-line comment must contain '--' characters at the beginning of the comment line:
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<table width="100%" border="0" cellpadding="0" cellspacing="0"><tr valign="top"><td width="14"></td><td><span style="font-family:Helvetica,Arial; font-size:4pt; color:#000000"></span></span><span style="font-family:Courier New; font-size:8pt; color:#000000"><span style="font-family:Courier New; font-size:8pt; color:#000080"><i>-- This query uses emp_db.abs database</i></span></span><span style="font-family:Courier New; font-size:8pt; color:#000000">
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</span></td></tr></table><table width="100%" border="0" cellpadding="0" cellspacing="0"><tr valign="top"><td width="14"></td><td><span style="font-family:Courier New; font-size:8pt; color:#000000"><b>SELECT</b> * <b>FROM</b> Employee
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</span></td></tr></table><table width="100%" border="0" cellpadding="0" cellspacing="0"><tr valign="top"><td width="14"></td><td><span style="font-family:Courier New; font-size:8pt; color:#000000"></span></td></tr></table><span style="font-family:Courier New; font-size:8pt; color:#000000"></span><span style="font-family:Helvetica,Arial; font-size:10pt; color:#000000">Multi-line comment must be enclosed in /* and */ characters.
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The following example uses multi-line comment to exclude temporarily some parts of the SQL statement.
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<table width="100%" border="0" cellpadding="0" cellspacing="0"><tr valign="top"><td width="14"></td><td><span style="font-family:Helvetica,Arial; font-size:4pt; color:#000000"></span></span><span style="font-family:Courier New; font-size:8pt; color:#000000"><b>SELECT</b> * <b>FROM</b> Employee
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</span></td></tr></table><table width="100%" border="0" cellpadding="0" cellspacing="0"><tr valign="top"><td width="14"></td><td><span style="font-family:Courier New; font-size:8pt; color:#000000"><span style="font-family:Courier New; font-size:8pt; color:#000080"><i>/* WHERE EmpNo < 5
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</i></span></i></span></td></tr></table><table width="100%" border="0" cellpadding="0" cellspacing="0"><tr valign="top"><td width="14"></td><td><span style="font-family:Courier New; font-size:8pt; color:#000080"><i>ORDER BY EmpNo */</i></span><span style="font-family:Courier New; font-size:8pt; color:#000000">
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