# Database Cheatsheet

## Quick Reference

| Key | Action |
|-----|--------|
| `<leader>Du` | Toggle DBUI |
| `<leader>Da` | Add connection |
| `<leader>Df` | Find DB buffer |

## Opening DBUI

```
<leader>Du    Toggle database UI
<leader>Da    Add new connection
```

## Connection Strings

### PostgreSQL

```
postgresql://user:password@localhost:5432/dbname
postgres://user:password@localhost/dbname

# With SSL
postgresql://user:password@host:5432/dbname?sslmode=require
```

### SQLite

```
sqlite:path/to/database.db
sqlite:./local.db
sqlite::memory:
```

## DBUI Navigation

```
<cr>          Toggle node / Execute query
o             Open node
R             Refresh
d             Delete
r             Rename
S             Sort by
H             Toggle help
q             Close
```

## Writing Queries

1. `<leader>Du` - Open DBUI
2. Navigate to database
3. Press `<cr>` on "New Query"
4. Write SQL
5. `<leader>Rs` or `<cr>` to execute

## Query Execution

In a `.sql` buffer connected to DBUI:

```
<cr>          Execute query under cursor
<leader>Rs    Execute query (visual: selected)
```

## Table Helpers

Right-click or press `<cr>` on a table for quick actions:

### PostgreSQL
- Count: `SELECT COUNT(*) FROM table`
- First10: `SELECT * FROM table LIMIT 10`
- Schema: `\d+ table`

### SQLite
- Count: `SELECT COUNT(*) FROM table`
- First10: `SELECT * FROM table LIMIT 10`
- Schema: `.schema table`

## Buffer Management

```
<leader>Df    Find DB buffer
<leader>Dr    Rename DB buffer
<leader>Dl    Last query info
```

## Common Workflows

### Connect to Database

1. `<leader>Da` - Add connection
2. Enter connection string
3. Give it a name
4. Connection saved for future sessions

### Explore Schema

1. `<leader>Du` - Open DBUI
2. Expand database node
3. Expand "Tables" node
4. `<cr>` on table for helpers

### Run Ad-hoc Query

1. `<leader>Du` - Open DBUI
2. Navigate to database
3. New Query
4. Write SQL:
   ```sql
   SELECT * FROM users WHERE active = true LIMIT 10;
   ```
5. Execute with `<cr>`

### Export Results

After running query:
1. Results appear in split
2. `:w filename.csv` to save

## Tips

### Multiple Databases

- Add multiple connections
- Switch by selecting in DBUI
- Each buffer tracks its connection

### Environment Variables

Connection strings can use env vars:
```
postgresql://$DB_USER:$DB_PASS@$DB_HOST/$DB_NAME
```

### SSH Tunnels

For remote databases, set up SSH tunnel first:
```bash
ssh -L 5432:localhost:5432 user@server
```

Then connect to `localhost:5432`.

## Troubleshooting

### Connection Failed

- Check credentials
- Verify database is running
- Check firewall/network

### Missing Adapter

Run `:checkhealth` and verify:
- `vim-dadbod` installed
- Database client available (psql, sqlite3)

### Slow Queries

- Add `LIMIT` to large tables
- Use `EXPLAIN` to analyze