JpaProvider (Blazebit Persistence Core API 1.2.0-Alpha2 API)

```
public interface JpaProvider
```
A JPA provider implementation provides information about which features are supported by a JPA implementation.

Since:

1.2.0

Author:

Christian Beikov

Method Summary

Methods
Modifier and Type	Method and Description
`String`	`escapeCharacter(char character)` The given escape character for a LIKE predicate as string.
`String`	`getBooleanConditionalExpression(boolean value)` The JPQL conditional expression to use for the given literal boolean value.
`String`	`getBooleanExpression(boolean value)` The JPQL expression to use for the given literal boolean value.
`String`	`getCollectionValueFunction()` Normally returns `VALUE`, but since Hibernate does weird things when using that, it returns `null`.
`String`	`getCustomFunctionInvocation(String functionName, int argumentCount)` Returns the start of a JPQL representation of a function invocation for the given function name and argument count.
`Class<?>`	`getDefaultQueryResultType()` The default result type of a scalar query.
`String`	`getNullExpression()` The JPQL expression to use for the NULL literal.
`String`	`getOnClause()` The name of the clause that has the same semantics as the ON clause which was introduced in JPA 2.1.
`boolean`	`isBag(javax.persistence.metamodel.Attribute<?,?> attribute)` Whether the given attribute is a non-indexed and non-ordered collection a.k.a. a bag.
`boolean`	`isJoinTable(javax.persistence.metamodel.Attribute<?,?> attribute)` Whether the given attribute is a collection that uses a join table.
`boolean`	`needsBracketsForListParamter()` Whether brackets are needed around a list parameter.
`boolean`	`needsJoinSubqueryRewrite()` Returns whether key restricted left joins should be rewritten to subquery joins.
`void`	`renderNullPrecedence(StringBuilder sb, String expression, String resolvedExpression, String order, String nulls)` Renders the null precedence into the given string builder.
`boolean`	`supportsCollectionValueDereference()` Whether dereferencing a VALUE function expression is supported by the JPA provider.
`boolean`	`supportsCountStar()` Whether the `COUNT(*)` syntax is supported.
`boolean`	`supportsEntityJoin()` Whether Entity Joins are supported.
`boolean`	`supportsInsertStatement()` Whether Insert statements are supported.
`boolean`	`supportsJpa21()` Whether JPA 2.1 specification is supported.
`boolean`	`supportsNullPrecedenceExpression()` Whether the query language supports the null precedence clause.
`boolean`	`supportsRootTreat()` Whether treating a from/root alias is supported.
`boolean`	`supportsRootTreatJoin()` Whether a root treat in a treat join is supported.
`boolean`	`supportsSingleValuedAssociationIdExpressions()` Indicates if the provider supports expressions like doc.owner.id without generating an extra join.
`boolean`	`supportsSubtypePropertyResolving()` Whether properties accessed of a from node are implicitly resolved to properties of a subtype of the from node.
`boolean`	`supportsTreatJoin()` Whether a treat join is supported.

- Method Detail
  - supportsJpa21
```
boolean supportsJpa21()
```
    Whether JPA 2.1 specification is supported.
    
    Returns:
    True if JPA 2.1 is supported, false otherwise
  - supportsEntityJoin
```
boolean supportsEntityJoin()
```
    Whether Entity Joins are supported.
    
    Returns:
    True if Entity Joins are supported, false otherwise
  - supportsInsertStatement
```
boolean supportsInsertStatement()
```
    Whether Insert statements are supported.
    
    Returns:
    True if Insert statements are supported, false otherwise
  - needsBracketsForListParamter
```
boolean needsBracketsForListParamter()
```
    Whether brackets are needed around a list parameter.
    
    Returns:
    True if brackets are needed, false otherwise
  - needsJoinSubqueryRewrite
```
boolean needsJoinSubqueryRewrite()
```
    Returns whether key restricted left joins should be rewritten to subquery joins. This is part of the workaround for https://hibernate.atlassian.net/browse/HHH-9329 which makes key restricted left joins wrong.
    
    Returns:
    true if joins should be rewritten to subquery joins, false otherwise
  - getBooleanExpression
```
String getBooleanExpression(boolean value)
```
    The JPQL expression to use for the given literal boolean value. This expression is used in contexts where an expression is assumed.
    
    Parameters:
    value - The boolean value
    
    Returns:
    The JPQL expression to use to reflect the boolean value
  - getBooleanConditionalExpression
```
String getBooleanConditionalExpression(boolean value)
```
    The JPQL conditional expression to use for the given literal boolean value. This expression is used in contexts where a predicate is assumed.
    
    Parameters:
    value - The boolean value
    
    Returns:
    The JPQL conditional expression to use to reflect the boolean value
  - getNullExpression
```
String getNullExpression()
```
    The JPQL expression to use for the NULL literal.
    
    Returns:
    The JPQL expression to use to reflect the NULL value
  - getOnClause
```
String getOnClause()
```
    The name of the clause that has the same semantics as the ON clause which was introduced in JPA 2.1.
    
    Returns:
    The name of the ON clause
  - getCollectionValueFunction
```
String getCollectionValueFunction()
```
    Normally returns VALUE, but since Hibernate does weird things when using that, it returns null. Returning null results in omitting VALUE in the final query that is passed to the JPA provider.
    
    Returns:
    The value function
  - supportsCollectionValueDereference
```
boolean supportsCollectionValueDereference()
```
    Whether dereferencing a VALUE function expression is supported by the JPA provider.
    
    Returns:
    True if dereferencing is supported, false otherwise
    Since:
    
    1.2.0
  - getDefaultQueryResultType
```
Class<?> getDefaultQueryResultType()
```
    The default result type of a scalar query.
    
    Returns:
    The default result type
  - getCustomFunctionInvocation
```
String getCustomFunctionInvocation(String functionName,
                                 int argumentCount)
```
    Returns the start of a JPQL representation of a function invocation for the given function name and argument count. Normally this returns FUNCTION('functionName', but implementations may also allow to render the function name directly.
    
    Parameters:
    functionName - The function name
    argumentCount - The number of the arguments that the function is invoked with
    
    Returns:
    The start of the JPQL represenation for the function invocation
  - escapeCharacter
```
String escapeCharacter(char character)
```
    The given escape character for a LIKE predicate as string.
    
    Parameters:
    character - The escape character
    
    Returns:
    The string representation
  - supportsNullPrecedenceExpression
```
boolean supportsNullPrecedenceExpression()
```
    Whether the query language supports the null precedence clause.
    
    Returns:
    True if the null precedence clause is supported, false otherwise
  - renderNullPrecedence
```
void renderNullPrecedence(StringBuilder sb,
                        String expression,
                        String resolvedExpression,
                        String order,
                        String nulls)
```
    Renders the null precedence into the given string builder.
    
    Parameters:
    sb - The builder to which the null precedence should be appended to
    expression - The order by expression which might be a select alias
    resolvedExpression - The resolved expression for a possible select alias or the expression
    order - The order as string (ASC or DESC)
    nulls - The null precedence as string (NULLS FIRST or NULLS LAST)
  - supportsRootTreat
```
boolean supportsRootTreat()
```
    Whether treating a from/root alias is supported.
    
    Returns:
    True if treating a from alias is supported, false otherwise
  - supportsTreatJoin
```
boolean supportsTreatJoin()
```
    Whether a treat join is supported.
    
    Returns:
    True if a treat join is supported, false otherwise
  - supportsRootTreatJoin
```
boolean supportsRootTreatJoin()
```
    Whether a root treat in a treat join is supported.
    
    Returns:
    True if a root treat in a treat join is supported, false otherwise
  - supportsSubtypePropertyResolving
```
boolean supportsSubtypePropertyResolving()
```
    Whether properties accessed of a from node are implicitly resolved to properties of a subtype of the from node.
    
    Returns:
    True if subtype property resolving is supported, false otherwise
  - supportsCountStar
```
boolean supportsCountStar()
```
    Whether the COUNT(*) syntax is supported.
    
    Returns:
    True if COUNT(*) syntax is supported, false otherwise
  - isJoinTable
```
boolean isJoinTable(javax.persistence.metamodel.Attribute<?,?> attribute)
```
    Whether the given attribute is a collection that uses a join table.
    
    Parameters:
    attribute - The attribute to check
    
    Returns:
    True if uses a join table, false otherwise
  - isBag
```
boolean isBag(javax.persistence.metamodel.Attribute<?,?> attribute)
```
    Whether the given attribute is a non-indexed and non-ordered collection a.k.a. a bag.
    
    Parameters:
    attribute - The attribute to check
    
    Returns:
    True if it is a bag, false otherwise
  - supportsSingleValuedAssociationIdExpressions
```
boolean supportsSingleValuedAssociationIdExpressions()
```
    Indicates if the provider supports expressions like doc.owner.id without generating an extra join.
    
    Returns:
    true if supported, else fales

Interface JpaProvider

Method Summary

Method Detail

supportsJpa21

supportsEntityJoin

supportsInsertStatement

needsBracketsForListParamter

needsJoinSubqueryRewrite

getBooleanExpression

getBooleanConditionalExpression

getNullExpression

getOnClause

getCollectionValueFunction

supportsCollectionValueDereference

getDefaultQueryResultType

getCustomFunctionInvocation

escapeCharacter

supportsNullPrecedenceExpression

renderNullPrecedence

supportsRootTreat

supportsTreatJoin

supportsRootTreatJoin

supportsSubtypePropertyResolving

supportsCountStar

isJoinTable

isBag

supportsSingleValuedAssociationIdExpressions