Contents
- 1 How to keep nulls or default values during bulk import?
- 2 How to add a NOT NULL constraint on pg faster?
- 3 How to add a NOT NULL constraint to a column?
- 4 Can a BCP command retain the null value?
- 5 What’s the maximum number of columns you can put in Bulk insert?
- 6 Why do I get null pointer exception in Java?
How to keep nulls or default values during bulk import?
Keep nulls or default values during bulk import (SQL Server) By default, when data is imported into a table, the bcp command and BULK INSERT statement observe any defaults that are defined for the columns in the table. For example, if there is a null field in a data file, the default value for the column is loaded instead.
How to add a NOT NULL constraint on pg faster?
Subsequent inserts or updates, however, will be enforced. Essentially this removes the potentially lengthy initial check on your table. This operation still gets an ‘EXCLUSIVE LOCK’, impeding writes on the table, but since it will not validate all the rows, it will be very quick: 6 ms (still on our demo env). Bull’s eye!
How to add a NOT NULL constraint to a column?
When you try to add a NOT NULL constraint onto a column, it will be executed on PostgreSQL as an atomic operation like: ALTER TABLE table_name ALTER COLUMN column_name SET NOT NULL; As a consequence, PostgreSQL will: fully scan the table to check that the constraint is valid on all the rows
How to prevent users from leaving fields blank?
One way to prevent incomplete records is to keep users from entering them at all. For example, say you’ve created a form for a table that lists the contact information of your customers. Since you carry on most of your business over the phone, it is necessary that each record contains both a work number and a cell phone number.
How many operations can be performed in bulk?
With an unordered bulk operation, the operations in the list may be reordered to increase performance. As such, applications should not depend on the ordering when performing unordered bulk operations. Each group of operations can have at most 1000 operations.
Can a BCP command retain the null value?
The bcp command and BULK INSERT statement both allow you to specify that nulls values be retained. In contrast, a regular INSERT statement retains the null value instead of inserting a default value.
What’s the maximum number of columns you can put in Bulk insert?
When using a format file with BULK INSERT, you can specify up to 1024 fields only. This is same as the maximum number of columns allowed in a table. If you use a format file with BULK INSERT with a data file that contains more than 1024 fields, BULK INSERT generates the 4822 error.
Why do I get null pointer exception in Java?
Whenever i try to run the TestDetails.java file i get a NullPointerException and the stack trace points the stack trace towards the File object. So what is the problem here?