Export Schema Validation Gate
Every export script in this catalogue writes a header row and a fixed column shape, but nothing checks afterward that the shape is still intact. A file that has been through email, a spreadsheet re-save, or manual editing can end up with a reordered column, a truncated row, or a value that quietly turned into text where a number was expected - and none of that throws an error on its own. It just makes every downstream number land in the wrong place, silently. This script reads a small, documented "schema description" text file - one line per expected column, in order, giving its name and type - and checks a CSV data file against it column by column, row by row. Anything wrong is reported with the exact row number and column name: a header that doesn't match, a row with the wrong field count, a value that isn't a valid int/double/date for its column. A full CSV report of every problem is also written alongside the journal output, so a long list of failures can be opened and worked through in a spreadsheet rather than scrolled through in the Experts tab. The schema description format is deliberately tiny - one line per column, "name:type" or "name:type:optional" - so a schema file for any export in this catalogue (or any external CSV) can be written by hand in under a minute rather than needing a separate schema-authoring tool. Notes and limitations This checks shape and value format, not business meaning - a schema saying a column is "double" accepts -999999.99 just as happily as a sane price. It catches structural corruption (reordered/missing columns, wrong field count, text where a number belongs), not domain-level nonsense. Field parsing has no quoting support of its own for the schema file, but the data file is read through FILE_CSV mode, which already handles quoted fields containing the delimiter the same way any other CSV export in this catalogue writes them. A completely empty data file (header only, or nothing at all) reports 0 rows checked and 0 problems - that is a pass on structure, but an empty export is very likely still worth a second look on its own.
Script · MT5 · v1.0 · Free
About Export Schema Validation Gate
Export Schema Validation Gate is a script for MetaTrader 5. It can alert you with a pop-up, sound, email or push message. It has 3 settings, such as Schema file, Data file and Max errors to print. MQL source code included.
Files in the download: ExportSchemaValidator.ex5, ExportSchemaValidator.mq5, ExportSchemaValidator.txt.
Settings
| Setting | Default | What it does |
|---|---|---|
| Schema file | Schema description file, in MQL5\Files (see .txt for the mini-format) | |
| Data file | CSV data file to validate, in MQL5\Files | |
| Max errors to print | 50 | Stop printing after this many error lines (the CSV report still lists all) |
How to install
- Download the ZIP from your PolyMaria library and unzip it.
- In MetaTrader 5 open File → Open Data Folder, then go to MQL5 → Scripts.
- Copy the .mq5 file(s) there. Put any .mqh files in MQL5 → Include.
- Open the .mq5 file in MetaEditor and press Compile (F7) if MetaTrader does not show it.
- Drag the script onto a chart to run it once.
Tags: Alerts · MT5 Script · MQL5 Source Code