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Remove redundant FOR from multiple pivot statements #367

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Remove redundant FOR from multiple pivot statements #367

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42 changes: 21 additions & 21 deletions documentation/query/sql/pivot.md
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Original file line number Diff line number Diff line change
Expand Up @@ -15,7 +15,7 @@ This is useful for analytics, charting, and transforming time-series sensor data
PIVOT (
aggregateExpression [ AS alias ] [, aggregateExpression [ AS alias ] ...]
FOR pivotExpression IN ( valueList | selectDistinctQuery )
[ FOR pivotExpression IN ( valueList | selectDistinctQuery ) ... ]
[ pivotExpression IN ( valueList | selectDistinctQuery ) ... ]
[ GROUP BY column [, column ...] ]
) [ AS alias ]
[ ORDER BY column [, column ...] ]
Expand Down Expand Up @@ -116,10 +116,10 @@ FROM trades
GROUP BY symbol;
```

| symbol | avg |
|---------|-----------|
| BTC-USD | 39267.64 |
| ETH-USD | 2615.42 |
| symbol | avg |
| ------- | -------- |
| BTC-USD | 39267.64 |
| ETH-USD | 2615.42 |

Without `PIVOT`, converting rows to columns requires verbose `CASE` expressions:

Expand All @@ -139,9 +139,9 @@ trades PIVOT (
);
```

| BTC-USD | ETH-USD |
|-----------|----------|
| 39267.64 | 2615.42 |
| BTC-USD | ETH-USD |
| -------- | ------- |
| 39267.64 | 2615.42 |

### Multiple aggregates

Expand All @@ -154,7 +154,7 @@ trades PIVOT (
```

| BTC-USD_avg_price | BTC-USD_half_value | ETH-USD_avg_price | ETH-USD_half_value |
|-------------------|--------------------|-------------------|--------------------|
| ----------------- | ------------------ | ----------------- | ------------------ |
| 39267.64 | 24500.12 | 2615.42 | 588.25 |

### Multiple FOR clauses (Cartesian product)
Expand All @@ -168,7 +168,7 @@ trades PIVOT (
```

| BTC-USD_buy | BTC-USD_sell | ETH-USD_buy | ETH-USD_sell |
|-------------|--------------|-------------|--------------|
| ----------- | ------------ | ----------- | ------------ |
| 39300.00 | 39267.64 | 2620.00 | 2615.54 |

### With GROUP BY
Expand All @@ -183,10 +183,10 @@ trades PIVOT (
) ORDER BY side;
```

| side | BTC-USD | ETH-USD |
|------|-----------|----------|
| buy | 39300.00 | 2620.00 |
| sell | 39267.64 | 2615.54 |
| side | BTC-USD | ETH-USD |
| ---- | -------- | ------- |
| buy | 39300.00 | 2620.00 |
| sell | 39267.64 | 2615.54 |

:::note
When a GROUP BY key has no matching FOR values in the data, the entire row is
Expand Down Expand Up @@ -274,13 +274,13 @@ trades PIVOT (
-- Columns: BTC-USD_avg_price, BTC-USD_total_price, ETH-USD_avg_price, ETH-USD_total_price
```

| Scenario | Example | Column name |
|----------|---------|-------------|
| Single aggregate | `avg(price) FOR symbol IN ('BTC')` | `BTC` |
| Multiple aggregates | `avg(price), sum(price) FOR symbol IN ('BTC')` | `BTC_avg(price)`, `BTC_sum(price)` |
| Multiple FOR | `avg(price) FOR symbol IN ('BTC') side IN ('buy')` | `BTC_buy` |
| With alias on value | `FOR symbol IN ('BTC-USD' AS btc)` | `btc` |
| With alias on aggregate | `avg(price) AS avg_price FOR symbol IN ('BTC')` | `BTC_avg_price` |
| Scenario | Example | Column name |
| ----------------------- | -------------------------------------------------- | ---------------------------------- |
| Single aggregate | `avg(price) FOR symbol IN ('BTC')` | `BTC` |
| Multiple aggregates | `avg(price), sum(price) FOR symbol IN ('BTC')` | `BTC_avg(price)`, `BTC_sum(price)` |
| Multiple FOR | `avg(price) FOR symbol IN ('BTC') side IN ('buy')` | `BTC_buy` |
| With alias on value | `FOR symbol IN ('BTC-USD' AS btc)` | `btc` |
| With alias on aggregate | `avg(price) AS avg_price FOR symbol IN ('BTC')` | `BTC_avg_price` |

## Limits

Expand Down