# Connectors for files and relational databases

*Tableau Data Analyst Study Guide · Connect To and Transform Data · Last updated October 29, 2026 · https://www.certifyforce.com/study-guide/tableau-data-analyst/connect-to-and-transform-data/connectors-for-files-and-relational-databases*

Pick the connector a source needs (Text File, Excel, PDF File, a native database connector or the ODBC fallback), fix delimited files with Text file properties, scan the right PDF pages, and choose Initial SQL or Custom SQL on a relational connection, including parameters and duplicate-column errors.

- Certification: Salesforce Tableau Data Analyst
- Exam section: Connect To and Transform Data
- Study guide: https://www.certifyforce.com/study-guide/tableau-data-analyst

**Official exam objective:**

> Connect to data sources: Identify data source; Determine live connection vs. extract; Connect to extracts; Connect to files; Connect to relational databases; Connect to published data sources from a Tableau Server or Tableau Cloud site; Replace the connected data source with another data source for an existing chart or sheet.

## What the exam expects

- Identify the data source and pick its connector, using Other Databases (ODBC) only when nothing native is listed.
- Connect to files correctly: set Text file properties (separator, text qualifier, character set, locale), connect to Excel tables and named ranges, and scan the right PDF pages.
- Connect to relational databases and choose Initial SQL (session setup, per-user security) or Custom SQL (a query used as a table), including parameters and duplicate column names.
- Live versus extract, extracts, published data sources and Replace Data Source are taught in Live connections, extracts and published data sources (basics: the Desktop Foundations units Live connections and extracts and Saved data sources and multiple connections).

Key terms:
- **Native connector:** a connector built for one file or database type.
- **Text file properties:** settings that tell Tableau how to parse a delimited file.
- **Initial SQL:** a command sent to the database when a connection is made.
- **Custom SQL:** a single SELECT query Tableau uses as a table.
- **TableauServerUser:** an Initial SQL parameter holding the signed-in server user's name.

## Key facts

| Fact | Detail | Source |
|---|---|---|
| Text File extensions | .txt, .csv, .tab, .tsv | [Text File](https://help.tableau.com/current/pro/desktop/en-us/examples_text.htm) |
| Excel connector | .xls and .xlsx; a .csv uses Text File | [Excel](https://help.tableau.com/current/pro/desktop/en-us/examples_excel.htm) |
| Locale setting | Tells Tableau which decimal and thousands separator to use | [Text File](https://help.tableau.com/current/pro/desktop/en-us/examples_text.htm) |
| PDF page numbers | First page of the file is page 1; use the reader's number | [PDF File](https://help.tableau.com/current/pro/desktop/en-us/examples_pdf.htm) |
| PDF wildcard union | Scoped to the pages scanned in the first file | [PDF File](https://help.tableau.com/current/pro/desktop/en-us/examples_pdf.htm) |
| ODBC | Only when no native connector is listed | [Other Databases (ODBC)](https://help.tableau.com/current/pro/desktop/en-us/examples_otherdatabases.htm) |
| TableauServerUser | Returns an empty string if the user isn't signed in to Tableau Server | [Run Initial SQL](https://help.tableau.com/current/pro/desktop/en-us/connect_basic_initialsql.htm) |
| Custom SQL shape | One SELECT statement, wrapped by Tableau | [Connect to a Custom SQL Query](https://help.tableau.com/current/pro/desktop/en-us/customsql.htm) |
| Custom SQL parameters | Literal values only, not table names | [Connect to a Custom SQL Query](https://help.tableau.com/current/pro/desktop/en-us/customsql.htm) |

## Check yourself

- Why does a table that spans two PDF pages arrive as several tables?
- When does Initial SQL run?
- Why do slow or failing Custom SQL queries often trace to Tableau itself?

## Sources

- [Connect to Your Data](https://help.tableau.com/current/pro/desktop/en-us/basicconnectoverview.htm)
- [Text File](https://help.tableau.com/current/pro/desktop/en-us/examples_text.htm)
- [Excel](https://help.tableau.com/current/pro/desktop/en-us/examples_excel.htm)
- [PDF File](https://help.tableau.com/current/pro/desktop/en-us/examples_pdf.htm)
- [Other Databases (ODBC)](https://help.tableau.com/current/pro/desktop/en-us/examples_otherdatabases.htm)
- [Run Initial SQL](https://help.tableau.com/current/pro/desktop/en-us/connect_basic_initialsql.htm)
- [Connect to a Custom SQL Query](https://help.tableau.com/current/pro/desktop/en-us/customsql.htm)

## About the full unit

The "Core concepts", "Exam traps" and "Worked scenario" sections of this unit, its 7 linked practice questions, and unlimited timed mock exams are included with the Tableau Data Analyst pack (USD $19): https://www.certifyforce.com/practice-exams