Withdata DataFileConverter merges SQL files into one fixedwidth file locally —
any number of files, mapped column by column, with the output options of your choice.
100% local, secure, and cross-platform.
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Why Choose Withdata DataFileConverter as a SQL Merger?
🔒 100% Local & Secure
All merging runs on your own computer. Nothing is uploaded to any cloud server.
⚡ Fast Streaming Merge
Millions of rows within a minute. Large files are streamed with low memory usage.
📁 Any Number of Files
Add two files or a whole folder, then combine everything into a single Fixed-Width Text file.
🔄 Column Mapping
Files with a different column order or extra columns can be mapped to the output columns before merging.
🖥 Windows, macOS, Linux
Native builds for Windows, macOS and Linux, with a step-by-step GUI wizard and a command line interface.
⏱ CLI & Scheduled Tasks
Save a merge session and run it automatically from Windows Task Scheduler or crontab.
Full Feature Comparison
| Feature | Supported details |
| Input | Any number of SQL files, added one by one or as a folder |
| Output format | Fixed-width text with auto-detected or custom column widths |
| Merge mode | All input rows into one output file |
| Running mode | GUI wizard · command line · scheduled tasks |
| Column handling | Source columns are mapped to the output columns |
| Output options | Column widths (auto-detected or manual), header row, encoding |
| Platform | Windows, macOS, Linux (native, 64-bit) |
SQL to Fixed-Width Text — What Changes
Table rows are written without delimiters, one fixed-width line per row. The column order follows the CREATE statement and the widths come from the merged values.
All SQL Merge Options You Need
Same source format, other targets
This page merges SQL into another format. If you need a different output, these pages each do that one job:
All merge tools, by format
Merging into Fixed-Width Text — Notes
- There is no delimiter and no quoting — every column has a fixed width.
- Merged output widths are measured from the data (widest value plus 15% slack, at least 2 and at most 15 extra characters) and can be edited.
- For N columns, N-1 widths are used — the last column takes the rest of the line.
- When reading fixed-width files: N columns need N-1 widths, no delimiter is used, and the header row is optional.
- The merged rows can be written as
INSERT statements, or as UPDATE/UPSERT using a multi-column key.
How to Merge SQL Files (4 Steps)
- Open Withdata DataFileConverter and choose Merge (combine multiple files into one).
- Add the SQL files you want to merge — two files, a list, or a whole folder.
- Check the preview and map the source columns to the output columns; then set the output options (Column widths (auto-detected or manual), header row, encoding).
- Click Convert — the single Fixed-Width Text file is written in seconds. Save the session if you want to run it again from the command line.
Merge multiple SQL files into one Fixed-Width Text file in GUI
In GUI mode the merge is a step-by-step wizard: add the files, check the preview, map the columns, choose the Fixed-Width Text output options, and click Convert.
See Withdata DataFileConverter.
FAQ
It processes millions of rows within a minute. Large files are streamed with low memory usage.
Yes. Everything runs locally on your computer — nothing is uploaded to any server, so your data stays private.
Yes. Withdata DataFileConverter has native builds for Windows, macOS and Linux, with both a GUI and a command line.
The columns of every file are mapped to the output columns, so files with a different column order or extra columns can still be merged once they are mapped.
Yes. Any number of files can be added to the merge, and a whole folder can be added in one step.
Yes. Save the merge session in the GUI, then run it from the command line, Windows Task Scheduler or crontab.
They are measured from the merged data: the widest value plus 15% slack, at least 2 and at most 15 extra characters. You can edit them.
Yes. Fixed-width files are read positionally, so all the files being merged should use the same column widths.
Start Merging SQL Files Today
Download Withdata DataFileConverter for a free trial. Runs on Windows, macOS and Linux.
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