docs/api/sql/Raster-Operators/RS_Union.md

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# RS_Union

Introduction: Returns a combined multi-band raster from 2 or more input Rasters. The order of bands in the resultant raster will be in the order of the input rasters. For example if `RS_Union` is called on two 2-banded raster, raster1 and raster2, the first 2 bands of the resultant 4-banded raster will be from raster1 and the last 2 from raster 2.

!!!note
    If the provided input Rasters don't have same shape an IllegalArgumentException will be thrown.

![RS_Union](../../../image/RS_Union/RS_Union.svg "RS_Union")

Format:

```sql
RS_Union (raster1: Raster, raster2: Raster)
```

```sql
RS_Union (raster1: Raster, raster2: Raster, raster3: Raster)
```

```sql
RS_Union (raster1: Raster, raster2: Raster, raster3: Raster, raster4: Raster)
```

```sql
RS_Union (raster1: Raster, raster2: Raster, raster3: Raster, raster4: Raster, raster5: Raster)
```

```sql
RS_Union (raster1: Raster, raster2: Raster, raster3: Raster, raster4: Raster, raster5: Raster, raster6: Raster)
```

```sql
RS_Union (raster1: Raster, raster2: Raster, raster3: Raster, raster4: Raster, raster5: Raster, raster6: Raster, raster7: Raster)
```

Return type: `Raster`

Since: `v1.6.0`

SQL Example

```sql
SELECT RS_Union(raster1, raster2, raster3, raster4) FROM rasters
```

Output:

```
GridCoverage2D["g...
```