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ELT Insert-Select

ELT Insert-Select

Jul 23, 2024

Overview

Use this Snap to perform the INSERT INTO SELECT operation on the specified table. The Snap creates a table and inserts the data if the target table does not exist. After successfully running a Pipeline that contains this Snap, you can check for the data updates made to the target table in one of the following ways: 

  • Validate the Pipeline and review the Snap's output preview data.

  • Query the target table using ELT Select Snap for the latest data available.

  • Open the target database and check for the new data in the target table.

Prerequisites

  • A valid SnapLogic account to connect to the database in which you want to perform the INSERT INTO SELECT operation.

  • Your database account must have the following permissions:

    • SELECT privileges for the source table whose data you want to insert into the target table.

    • CREATE TABLE privileges for the database in which you want to create the table.

    • INSERT privileges to insert data into the target table.

Limitations

  • The input data must correspond to the specified table's schema. You can use the ELT Transform Snap to ensure this.

Known Issues

  • If the last Snap in the Pipeline takes 2 to 5 seconds to update the runtime, the ELT Pipeline statistics are not displayed even after the Pipeline is completed. The UI does not auto-refresh to display the statistics after the runtime.
    Workaround: Close the Pipeline statistics window and reopen it to see the ELT Pipeline statistics.

  • When you return to the Snap Statistics tab from the Extra Details tab in the Pipeline Execution Statistics pane, it contains the status bar (Pipeline execution status) instead of the Download Query Details hyperlink and the individual counts of Records Added, Records Updated, and Records Deleted.

  • When your Databricks Lakehouse Platform instance uses Databricks Runtime Version 8.4 or lower, ELT operations involving large amounts of data might fail due to the smaller memory capacity of 536870912 bytes (512MB) allocated by default. This issue does not occur if you are using Databricks Runtime Version 9.0.

  • Suggestions displayed for the Schema Name field in this Snap are from all databases that the Snap account user can access, instead of the specific database selected in the Snap's account or Settings.

Snap Input and Output

Input/Output

Type of View

Number of Views

Examples of Upstream and Downstream Snaps

Description

Input/Output

Type of View

Number of Views

Examples of Upstream and Downstream Snaps

Description

Input 

Document

  • Min: 1

  • Max: 1

  • ELT Select

  • ELT Transform

The data to be inserted into the target table. Ensure that the data corresponds to the target table's schema. 

Output

Document

  • Min: 0

  • Max: 1

  • ELT Select

  • ELT Transform

A document containing the SQL SELECT query executed on the target database.

Snap Settings

SQL Functions and Expressions for ELT

You can use the SQL Expressions and Functions supported for ELT to define your Snap or Account settings with the Expression symbol = enabled, where available. This list is common to all target CDWs supported. You can also use other expressions/functions that your target CDW supports.

Parameter Name

Data Type

Description

Default Value

Example 

Parameter Name

Data Type

Description

Default Value

Example 

Label

String

ELT Insert-Select

Insert Employee Records

Get preview data

Checkbox

Not selected

Selected

Database Name

String

Required. Enter the name of the database in which the target table is located. Leave it blank to use the database name specified in the account settings.

If your target database is Databricks Lakehouse Platform (DLP), you can, alternatively, mention the file format type for your table path in this field. For example, DELTA, CSV, JSON, ORC, AVRO. See Table Path Management for DLP section below to understand the Snap's behavior towards table paths.

N/A 

TESTDB

Schema Name (Not applicable to Databricks Lakehouse Platform)

String

Required. Enter the name of the database schema. In case it is not defined, then the suggestion for the schema name retrieves all schema names in the specified database when you click 

.

N/A

"TEST_DATA"

Target Table Name

String

Required. The name of the table or view into which you want to insert the data. 

Only views that can be updated (have new rows) are listed as suggestions. So, Join views are not included. This also implies that the Snap account user has the Insert privileges on the views listed as suggestions.

If your target database is Databricks Lakehouse Platform (DLP), you can, alternatively, mention the target table path in this field. Enclose the DBFS table path between two `(backtick/backquote) characters. For example, `/mnt/elt/mytabletarget`. Learn more about the Snap’s behavior toward paths in the Table Path Management for DLP section.

If you choose to include the schema name as part of the target table name, ensure that it is the same as specified in the Schema Name field, including the double quotes. For example, if the schema name specified is "table_schema_1", then the table name should be "table_schema_1"."tablename".

If the target table or view does not exist during run-time, the Snap creates one with the name that you specify in this field and writes the data into it. During Pipeline validation, the Snap creates the new table or view but does not write any records into it.

  • The new table or view will not be dropped if a subsequent/downstream Snap failure occurs during validation.

  • Use double quotes (““) to specify the table or view name if you want to include special characters such as hyphens (-) in the table or view name.

  • A table or view name must always start with a letter.

  • Integers and underscores (_) can also be a part of the name.

  • All characters are automatically converted to uppercase at the backend. Use double-quotes to retain lowercase.

 

N/A

"TEST_DATA"."DIRECT"

EMPLOYEE_DATA

EMPLOYEE_123_DATA

REVENUE"-"OUTLET

"net_revenue"

Advanced Options

Checkbox 

Select this checkbox to define the mapping of your source and target table columns scenario with or without the Insert Expressions list. When selected, it activates the Operation Types field.

Deselected

Selected

Operation Types

Dropdown list

Choose one of the following options that best describes your source data and the INSERT preference:

  • Source Columns Order. Use this operation type to fill the target table columns with the source table data in the same order of columns as in the source table.

  • Some Source and Target Column names are identical. Use this operation type when you want only a subset of the target table columns that are identical to the source to be filled with the source data and optionally define the Insert Expression List to fill the remaining columns in the target table.

  • All Source and Target Column names are identical. Use this operation type when your source and target table have the same set of column names. You cannot specify any Insert Expressions with this operation type.

Source Columns Order

Some Source and Target Column names are identical

Table Option List

This field set enables you to specify the table options you want to use on the target table. These options are populated based on the Snap Account (target CDW) selected. You must specify each table option in a separate row. Click

 to add rows. 

This field set contains one field:

  • Table Option

Table Option

String/Suggestion

Click the Suggestions icon ( 

 ) to view and select the table option you want to apply for loading data into the target table.

N/A

DISTRIBUTION = HASH ( cust_name )

Insert Expression List

This field set enables you to specify the values for a subset of the columns in the target table. The remaining columns are assigned null values automatically. You must specify each column in a separate row. Click

 to add rows. 

This field set is disabled if you select All Source and Target Column names are identical in the Operation Types field.

This field set consists of the following fields:

  • Insert Column

  • Insert Value

You can use this field set to insert data only into an existing table. 

Insert Column

String

Enter the name of the column in the target table to assign values.

N/A

ORD_AMOUNT

Insert Value

String

Enter the value to assign in the specified column. Repeat the column name if you want to use the values in the source table. You can also use expressions to transform the values.

N/A

ORD_AMOUNT

ORD_AMOUNT+20

Overwrite

Checkbox

Select to overwrite the data in the target table. If not selected, the incoming data is appended. 

Not selected

Selected

Snap behavior in different source and target table column scenarios

Data match (operation) type 

Number of source
table columns 

Number of target
table columns 

Insert expression
list specified? 

Snap behavior

Data match (operation) type 

Number of source
table columns 

Number of target
table columns 

Insert expression
list specified? 

Snap behavior

Not specified (Advanced Options checkbox is not selected)

Less

More

Yes

  • Ignores data in the source table columns.

  • Inserts values from the Expression list in the target table columns.

  • Inserts nulls in the remaining target columns.

  • Returns an error if the target table does not exist.

Not specified (Advanced Options checkbox is not selected)

Same

Same

Yes

  • Ignores data in the source table columns.

  • Inserts values from the Expression list in the target table columns.

  • Inserts nulls in the remaining target columns.

  • Returns an error if the target table does not exist.

Not specified (Advanced Options checkbox is not selected)

More

Less

Yes

  • Ignores data in the source table columns.

  • Inserts values from the Expression list in the target table columns.

  • Inserts nulls in the remaining target columns.

  • Returns an error if the target table does not exist.

Not specified (Advanced Options checkbox is not selected)

Less

More

No

  • Inserts values into the target table columns that match the source columns.

  • Inserts nulls in the remaining target columns.

Not specified (Advanced Options checkbox is not selected)

Same

Same

No

  • Inserts values into the target table columns that match the source columns.

  • Replicates the source table as a new target table, if the target table does not exist.

Not specified (Advanced Options checkbox is not selected)

More

Less

No

  • Inserts values into the target table columns that match the source columns.

  • Inserts nulls in the remaining target table columns.

  • Replicates the source table as a new target table, if the target table does not exist.

Source Columns Order

Less

More

No

  • Inserts values from the source in the matching target columns.

  • Inserts nulls in the remaining target columns.

Source Columns Order

Less

More

Yes

  • Inserts values from the source in the matching target columns.

  • Inserts values from the Insert expression list in the specified target columns.

  • Inserts nulls in the remaining target columns.

  • Returns an error if any specified column name is not found in the target table.

Source Columns Order

Same

Same

No

  • Inserts values from the source in the matching target columns.

Source Columns Order

Same

Same

Yes

  • Returns an error that the source table (combined with Insert Expression list) has more columns than the target table.

All Source and Target Column names are identical

Less

More

Not displayed

  • Inserts values from the source in the matching target columns.

  • Inserts nulls in the remaining target columns.

All Source and Target Column names are identical

Same

Same

Not displayed

  • Inserts values from the source in the matching target columns.

  • Inserts nulls in the remaining target columns.

Some Source and Target Column names are identical

Less

More

No

  • Inserts values from the source in the matching target columns.

  • Inserts nulls in the remaining target columns.

Some Source and Target Column names are identical

Less

More

Yes

  • Assumes that there is no column name in common between the source table and Insert expression list. Returns an error if a common column is found.

  • Inserts values from the source in the matching target columns.

  • Inserts values from the Insert Expression list in the specified target columns.

  • Inserts nulls in the remaining target columns.

  • Returns an error if any specified column name is not found in the target table.

Some Source and Target Column names are identical

Same

Same

No

  • Inserts values from the source in the matching target columns.

  • Inserts nulls in the remaining target columns.

Some Source and Target Column names are identical

Same

Same

Yes

  • Assumes that the sum of the source table columns count and the Insert Expression list is not more than the target table columns count. Returns an error if this condition is not satisfied.

  • Inserts values from the source in the matching target columns.

  • Inserts values from the Insert expression list in the specified target columns.

  • Inserts nulls in the remaining target columns.

  • Returns an error if any specified column name is not found in the target table.

Any of the three options

More 

Less

Yes or No

  • Returns an error that the source table (plus Insert expressions) has more columns than the target table and the Insert Select operation cannot be performed.

Table Path Management for DLP

A table path in Databricks Lakehouse Platform is the folder in the DBFS where the files corresponding to the target table are stored. You need to enclose the DBFS table path between two `(backtick/backquote) characters.

File Format Type
(Database Name field)

Table Path exists?#

All other requirements
are valid?

Snap Operation Result

File Format Type
(Database Name field)

Table Path exists?#

All other requirements
are valid?

Snap Operation Result

1

DELTA