SQL Server - Bulk Load

On this Page

Snap type:

Write


Description:

This Snap executes an SQL Server bulk load. The Snap uses the bcp utility program internally to perform the bulk load action. The input data is first written to a temporary data file, then the bcp utility program loads the data from the data file into the target table.

  • Expected upstream Snaps: The columns of the target table need to be mapped upstream using a Mapper Snap. The Mapper Snap will provide the target schema, which reflects the schema of the target table.
  • Expected downstream Snaps: None.
  • Expected input: Document that needs to be loaded.
  • Expected output: Document which represents the result of the bulk load operation.

Table Creation

If the table does not exist when the Snap tries to do the load, and the Create table property is set, the table will be created with the columns and data types required to hold the values in the first input document. If you would like the table to be created with the same schema as a source table, you can connect the second output view of a Select Snap to the second input view of this Snap. The extra view in the Select and Bulk Load Snaps are used to pass metadata about the table, effectively allowing you to replicate a table from one database to another.
 

The table metadata document that is read in by the second input view contains a dump of the JDBC DatabaseMetaData class. The document can be manipulated to affect the CREATE TABLE statement that is generated by this Snap. For example, to rename the name column to full_name, you can use a Mapper (Data) Snap that sets the path $.columns. Name.COLUMN_NAME to full_name.  The document contains the following fields:

  • columns - Contains the result of the getColumns() method with each column as a separate field in the object. Changing the COLUMN_NAME value will change the name of the column in the created table. Note that if you change a column name, you do not need to change the name of the field in the row input documents. The Snap will automatically translate from the original name to the new name. For example, when changing from name to full_name, the name field in the input document will be put into the "full_name" column. You can also drop a column by setting the COLUMN_NAME value to null or the empty string.  The other fields of interest in the column definition are:

    • TYPE_NAME - The type to use for the column.  If this type is not known to the database, the DATA_TYPE field will be used as a fallback.  If you want to explicitly set a type for a column, set the DATA_TYPE field.

    • _SL_PRECISION - Contains the result of the getPrecision() method.  This field is used along with the _SL_SCALE field for setting the precision and scale of a DECIMAL or NUMERIC field.

    • _SL_SCALE - Contains the result of the getScale() method.  This field is used along with the _SL_PRECISION field for setting the precision and scale of a DECIMAL or NUMERIC field.

  • primaryKeyColumns - Contains the result of the getPrimaryKeys() method with each column as a separate field in the object.

  • declaration - Contains the result of the getTables() method for this table. The values in this object are just informational at the moment.  The target table name is taken from the Snap property.

  • importedKeys - Contains the foreign key information from the getImportedKeys() method. The generated CREATE TABLE statement will include FOREIGN KEY constraints based on the contents of this object. Note that you will need to change the PKTABLE_NAME value if you changed the name of the referenced table when replicating it.

  • indexInfo - Contains the result of the getIndexInfo() method for this table with each index as a separate field in the object.  Any UNIQUE indexes in here will be included in the CREATE TABLE statement generated by this Snap.



  • A Joda DateTime object. For example, a Joda DateTime object can be created with expression Date.now() in Mapper Snap.
  • A plain string in the format: YYYY-MM-dd HH: mm:ss. Example: 2016-10-22 11:11:11.

 SQL Server Bulk Load Snap does not accept the results by the DateTime string from the expression Date.toLocaleDateTimeString().

 

Prerequisites:

The BCP utility must be installed on the Groundplex nodes on which you want to execute this Snap. To install the BCP utility on a Groundplex:

  1. Download and Install the BCP Utility in your Windows or Linux environment. For details on doing so, use the following links:
    1. Installing BCP on Linux
    2. Installing BCP on Windows
  2. Verify that you are able to run the bcp command.

    To verify BCP installation, enter bcp on the terminal or the command line console and press Enter.

    The output should look similar to the following. These are the command line options that can be used with the BCP utility. If you see this output, it means that the BCP utility is installed and ready for use.

  3. Ensure that the path to the bcp command is correctly provided in the Snap.
Troubleshooting

Problem: Some characters appear as junk values after bulk load.

Reason: The Snaplex uses character sets defined in the OS on which they are installed. Due to this, any unrecognized character set is not supported by the Snaplex as well. As a result, such characters in the data set are represented as junk values in the database after a bulk load operation.

Resolution: This problem can be resolved by editing the bcp.bat file to accept custom characters. And using the absolute path to this bcp file in the BCP absolute path property. The bcp.bat file must contain the following:

Support and limitations:

Does not work in Ultra Pipelines.

Account: 

This Snap uses account references created on the Accounts page of SnapLogic Manager to handle access to this endpoint. See Configuring SQL Server Accounts for information on setting up this type of account.


Views:
Input

This Snap has one document input view by default. 

A second view can be added for metadata for the table as a document so that the target absent table can be created in the database with a similar schema as the source table. This schema is usually from the second output of a database Select Snap. If the schema is from a different database, there is no guarantee that all the data types would be properly handled.

OutputThis Snap has at most one document output view.
Error

This Snap has at most one document error view and produces zero or more documents in the view.

Settings

Label


Required. The name for the Snap. You can modify this to be more specific, especially if you have more than one of the same Snap in your pipeline.

Schema Name


The database schema name. In case it is not defined, then the suggestion for the Table Name will retrieve all tables names of all schemas. The property is suggestible and will retrieve available database schemas during suggest values.

Example: SYS
Default value:  [None]


Table Name

Required. Table on which to execute the bulk load operation.


Example: people

Default value:  [None]

Examples:
Supported by BCP: "dbo"."sqldemo#^&$%"   
Not supported by BCP: "dbo"."sqldemo#^&%$"  


Create table if not present


Whether the table should be automatically created if it is not already present.


Default value: Not selected
 

BCP absolute path

The absolute path of the bcp utility program in JCC's file system. If empty, the Snap looks for it in JCC's environment variable PATH.

Example: C:\bcp.bat

Default value:  [None]

Handling Unrecognized Character sets in the Data set

Since the Snaplex uses the OS's default character set, it cannot recognize characters in other languages. Due to this, unrecognized characters in the data set are replaced with junk values when performing bulk load operations. To mitigate this, create a bcp.bat file and include the following line:

Use the path to this bcp.bat file in the BCP absolute path.

Maximum error count


Required. The maximum number of rows which can fail before the bulk load operation is stopped.

Default value:  10  


Indicates how the Snap must be executed. Available options are:

  • Validate & Execute: Performs limited execution of the Snap (up to 50 records) during Pipeline validation; performs full execution of the Snap (unlimited records) during Pipeline execution.
  • Execute only: Performs full execution of the Snap during Pipeline execution; does not execute the Snap during Pipeline validation.
  • Disabled: Disables the Snap and, by extension, its downstream Snaps.

Default value: Execute only

 Example


This example loads data from table bulk_test_source to table bulk_test_target with SQL Server Bulk Load Snap.

The pipeline:

The SQL Server Select Snap  gets records in the table bulk_test_source and passes them to the SQL Server Bulk Load Snap:

The SQL Server Bulk Load Snap that loads inputs to table bulk_test_target looks as follows:

The output of the SQL Server Bulk Load Snap after executing the pipeline:

Snap Pack History