CoalesceExpNode (LinuxForHealth FHIR Server)

java.lang.Object
- org.linuxforhealth.fhir.database.utils.query.node.CoalesceExpNode

All Implemented Interfaces:: ExpNode

public class CoalesceExpNode
extends java.lang.Object
implements ExpNode

The COALESCE SQL function

Constructor Summary

Constructors
Constructor Description

CoalesceExpNode(ColumnRef[] refs)
Public constructor

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`boolean`	`isOperand()`	Is this expression node an operand
`void`	`popOperands(java.util.Stack<ExpNode> stack)`	Read the operands from the stack
`int`	`precedence()`	Precedence of this expression node.
`<T> T`	`visit(ExpNodeVisitor<T> visitor)`	Generic evaluation visitor

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

Methods inherited from interface org.linuxforhealth.fhir.database.utils.query.node.ExpNode
isLeftParen, isOperator, isRightParen

- Constructor Detail
  - CoalesceExpNode
```
public CoalesceExpNode(ColumnRef[] refs)
```
    Public constructor
    
    Parameters:
    
    refs -
- Method Detail
  - visit
```
public <T> T visit(ExpNodeVisitor<T> visitor)
```
    Description copied from interface: ExpNode
    
    Generic evaluation visitor
    
    Specified by:
    
    visit in interface ExpNode
    
    Returns:
  - precedence
```
public int precedence()
```
    Description copied from interface: ExpNode
    
    Precedence of this expression node. Used to parse the expression into the correct tree. We use 0 to represent the highest precedence
    
    Specified by:
    
    precedence in interface ExpNode
    
    Returns:
  - popOperands
```
public void popOperands(java.util.Stack<ExpNode> stack)
```
    Description copied from interface: ExpNode
    
    Read the operands from the stack
    
    Specified by:
    
    popOperands in interface ExpNode
  - isOperand
```
public boolean isOperand()
```
    Description copied from interface: ExpNode
    
    Is this expression node an operand
    
    Specified by:
    
    isOperand in interface ExpNode
    
    Returns: