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How to create a copy of a table



Overview


Sometimes you want to create a copy of a table for a test case, or you might need to back up data from a rotated shard before it gets truncated.

Although you could create a backup of the table from the backend easily, you would not be able to access it from the instance, whether from a form or a list or from /sys.scripts.do. The application would not be aware that the new table exists because there would be no records in the application metadata tables (sys_db_object, sys_dictioary, sys_documentation, etc.).

This article describes how to create a copy of an existing table so that you can access the copied table from the UI or /sys.scripts.do.

Note: Note that the table will be empty and will not contain data. You have to copy data from the source table as a separate process.

 

Procedure


  1. Go to /sys.scripts.do.

  2. Copy the following code and customize it for your environment.

    The first argument is the source table, the table to be copied. The second argument is the new/target table. The third argument is Boolean: set it to false if you don't want to or need to create the indexes. (The creation time will be fast either way as the table will be empty.)

    cpTable('sys_upgrade_history_log', 'u_testcase', true);
     
    function cpTable(strOldTable, strNewTable, bCopyIndexes) {
        var tu = new TableUtils(strNewTable);
        var bNewTableAlreadyExists = tu.tableExists();
        if (bNewTableAlreadyExists) {
            gs.print("WARNING: Target Table " + strNewTable + " already exists!  Please choose a new target table name");
        } else {
            var gr = new GlideRecord(strOldTable);
            gr.initialize();
            var td = GlideTableDescriptor.get(strOldTable);
            var tdNewTable = new TableDescriptor(strNewTable, gr.getLabel());
            var dbo = new GlideRecord("sys_db_object");
            dbo.addEncodedQuery("super_classISNOTEMPTY^name=" + strOldTable);
            dbo.setLimit(1);
            dbo.query();
            if (dbo.next()) {
                tdNewTable.setExtends(dbo.super_class + '');
            }
            tdNewTable.setFields(gr);
            tdNewTable.copyAttributes(td);
            tdNewTable.setRoles(td);
            tdNewTable.create();
            if (bCopyIndexes) {
                tdNewTable.copyIndexes(strOldTable, strNewTable);
            }
        }
    }

  3. Click Run Script.

    The code will create a new table in the instance called u_testcase. You can now access this table via /u_testcase_list.do and from GlideRecord('u_testcase');.

    The output might look like the following example.

    [0:00:01.621] Script completed in scope global: script
    Creating table: u_testcase
    TableCreate for: u_testcase
    DBTable.create() for: u_testcase
    Replication is not enabled on table: u_testcase, not queueing replication table create special db event
    *** Script: Begin ResourceSupport.buildTableResources(u_testcase, undefined)
    *** Script: End ResourceSupport.buildTableResources
    LicensingTableCreateListener: Initializing licensing attrs for table u_testcase
    Time: 0:00:00.615 id: tundra_1[glide.2] for: SELECT sys_storage_alias0.`table_name`, sys_storage_alias0.`element_name`, sys_storage_alias0.`storage_alias` FROM sys_storage_alias sys_storage_alias0  WHERE sys_storage_alias0.`storage_alias` != sys_storage_alias0.`element_name` /* tundra004, gs:329947A4DBAE4700671C51035E9619B8, tx:52c94328dbae4700671c51035e9619cb */ 
    Creating index(es): ALTER TABLE `u_testcase`ADD INDEX (`sys_source_table`) ,ADD INDEX (`update_set`) ,ADD INDEX (`upgrade_history`) 
    Duplicate index, skipping: u_testcase([sys_source_table]) NONUNIQUE
    Duplicate index, skipping: u_testcase([update_set]) NONUNIQUE
    Redundant index check on u_testcase found redundant index upgrade_history (upgrade_history) NONUNIQUE; caused by new index (upgrade_history,file_name,sys_recorded_at) NONUNIQUE
    Redundant index check on u_testcase found 1 redundant indexes
    Creating index(es): ALTER TABLE `u_testcase`ADD INDEX (`upgrade_history`, `file_name`, `sys_recorded_at`) ,ADD INDEX (`upgrade_history`, `order`) ,ADD INDEX (`upgrade_history`, `disposition`, `resolution_status`, `changed`, `order`) ,ADD INDEX (`upgrade_history`, `resolution_status`, `disposition`, `type_priority`) ,ADD INDEX (`upgrade_history`, `disposition`, `changed`) ,ADD INDEX (`order`) 
    Dropping index(es): ALTER TABLE `u_testcase` DROP INDEX `upgrade_history`

    If you run the same code again, an error occurs:

    [0:00:00.000] Script completed in scope global: script
    *** Script: WARNING: Target Table u_testcase already exists! Please choose a new target table name

 

Article Information

Last Updated:2018-11-08 04:57:47
Published:2018-11-08