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SQL programmingYou can use the HCL OneDB™ implementation of the SQL language to develop applications for HCL OneDB™ database servers.
Guide to SQL: SyntaxThe HCL OneDB™ Guide to SQL: Syntax describes the syntax of the statements, data types, expressions, operators, and built-in functions of the HCL OneDB™ dialect of the SQL language.
SQL statementsThis chapter describes the syntax and semantics of SQL statements that are recognized by HCL OneDB™.
CREATE TABLE statementUse the CREATE TABLE statement to create a new permanent table in the current database.
Specialized columnsYou can create specialized columns to support Enterprise Replication, high availability, or row-level auditing.
Using the WITH CRCOLS Option

Using the WITH CRCOLS Option

Use the WITH CRCOLS keywords to create two shadow columns that Enterprise Replication uses for conflict resolution. The first column, cdrserver, contains the identity of the database server where the last modification occurred. The second column, cdrtime, contains the time stamp of the last modification. You must add these columns before you can use time stamps for UDR conflict resolution. These two columns are hidden shadow columns, because they cannot be indexed and cannot be viewed in system catalog tables.

For most database operations, the cdrserver and cdrtime columns are hidden. For example, if you include the WITH CRCOLS keywords when you create a table, the cdrserver and cdrtime columns have the following behavior:

They are not returned by queries that specify an asterisk ( * ) as the projection list, as in the statement:
```
SELECT * FROM tablename;
```
They do not appear in DB-Access when you ask for information about the columns of the table.
They are not included in the number of columns (ncols) in the systables system catalog table entry for tablename.

To view the contents of cdrserver and cdrtime, you must explicitly specify the columns in the projection list of a SELECT statement, as the following example shows:

SELECT cdrserver, cdrtime FROM tablename;

For more information about how to use this option, refer to the HCL OneDB™ Enterprise Replication Guide.

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