Expression (CsvJdbc 1.0.41 API)

java.lang.Object
- org.relique.jdbc.csv.Expression

Direct Known Subclasses:

SQLArrayAggFunction, SQLToArrayFunction
```
public abstract class Expression
extends Object
```

Constructor Summary

Constructors
Constructor Description

Expression()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`List<org.relique.jdbc.csv.AggregateFunction>`	`aggregateFunctions()`
`Object`	`eval(Map<String,Object> env)`
`boolean`	`isValid()`	Is this a valid expression such as A > 5 or an invalid mix of logical and arithmetic such as (A > 5) + 1 that we cannot detect during parsing.
`void`	`resetAggregateFunctions()`	Reset aggregate function each time it is used in a subquery.
`List<String>`	`usedColumns(Set<String> availableColumns)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - Expression
```
public Expression()
```
- Method Detail
  - eval
```
public Object eval(Map<String,Object> env)
            throws SQLException
```
    Throws:
    
    SQLException - if error evaluating expression.
  - usedColumns
```
public List<String> usedColumns(Set<String> availableColumns)
```
  - aggregateFunctions
```
public List<org.relique.jdbc.csv.AggregateFunction> aggregateFunctions()
```
  - isValid
```
public boolean isValid()
```
    Is this a valid expression such as A > 5 or an invalid mix of logical and arithmetic such as (A > 5) + 1 that we cannot detect during parsing.
    
    Returns:
    
    true if valid.
  - resetAggregateFunctions
```
public void resetAggregateFunctions()
```
    Reset aggregate function each time it is used in a subquery.