# SQLDOU vs Database Keys and Constraints

The clearest difference is in-app purchases: Database Keys and Constraints at none against SQLDOU's 1. Database Keys and Constraints also leads on ads (none vs shown). On price, device support and iOS requirement there is nothing between them.

Both are free to download. SQLDOU sells 1 one-off in-app purchase. Database Keys and Constraints asks for nothing beyond the download.

## The numbers

| Metric | SQLDOU | Database Keys and Constraints |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Every 3 weeks | — |
| Size | 10 MB | 38 MB |
| Requires iOS | 16.0 | **15.1** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Fuji Bit Inc.](https://appshunter.io/developer/1874205957) | [AFTW LLC](https://appshunter.io/developer/1886356149) |

## What reviewers say

### SQLDOU

[App page](https://appshunter.io/ios/app/sqldou/id6760616192)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| SQLDOU Pro | $5.99 | one-time |


### Database Keys and Constraints

[App page](https://appshunter.io/ios/app/database-keys-and-constraints/id6773622183)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is SQLDOU free?

SQLDOU is free to download, with in-app purchases available.

### Is Database Keys and Constraints free?

Database Keys and Constraints is free to download, with no in-app purchases.

### Do SQLDOU or Database Keys and Constraints have ads?

SQLDOU shows ads; Database Keys and Constraints does not.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*