本文整理了Java中com.querydsl.core.types.ExpressionUtils.eq()方法的一些代码示例，展示了ExpressionUtils.eq()的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。ExpressionUtils.eq()方法的具体详情如下：
包路径：com.querydsl.core.types.ExpressionUtils
类名称：ExpressionUtils
方法名：eq

ExpressionUtils.eq介绍

[英]Create a left == right expression
[中]创建一个left==right表达式

代码示例

代码示例来源：origin: querydsl/querydsl

/**
 * Create a {@code left == constant} expression
 *
 * @param <D> type of expressions
 * @param left lhs of expression
 * @param constant rhs of expression
 * @return left == constant
 */
public static <D> Predicate eqConst(Expression<D> left, D constant) {
  return eq(left, ConstantImpl.create(constant));
}

代码示例来源：origin: querydsl/querydsl

@Test
public void eq() {
  assertEquals("str = str2", ExpressionUtils.eq(str, str2).toString());
}

代码示例来源：origin: com.querydsl/querydsl-core

/**
 * Create a {@code left == constant} expression
 *
 * @param <D> type of expressions
 * @param left lhs of expression
 * @param constant rhs of expression
 * @return left == constant
 */
public static <D> Predicate eqConst(Expression<D> left, D constant) {
  return eq(left, ConstantImpl.create(constant));
}

代码示例来源：origin: com.querydsl/querydsl-sql

@SuppressWarnings("unchecked")
protected void addKeyConditions(FilteredClause<?> query) {
  List<? extends Path<?>> keys = getKeys();
  for (int i = 0; i < columns.size(); i++) {
    if (keys.contains(columns.get(i))) {
      if (values.get(i) instanceof NullExpression) {
        query.where(ExpressionUtils.isNull(columns.get(i)));
      } else {
        query.where(ExpressionUtils.eq(columns.get(i),(Expression) values.get(i)));
      }
    }
  }
}

代码示例来源：origin: com.querydsl/querydsl-sql

@SuppressWarnings("unchecked")
public Predicate on(RelationalPath<E> entity) {
  BooleanBuilder builder = new BooleanBuilder();
  for (int i = 0; i < localColumns.size(); i++) {
    Expression<Object> local = (Expression<Object>) localColumns.get(i);
    Expression<?> foreign = ExpressionUtils.path(local.getType(), entity, foreignColumns.get(i));
    builder.and(ExpressionUtils.eq(local,foreign));
  }
  return builder.getValue();
}

代码示例来源：origin: com.querydsl/querydsl-jpa

@SuppressWarnings("unchecked")
private void addCondition(Context context, int i, Path<?> path, boolean where) {
  paths.add(path);
  EntityPath<?> alias = context.replacements.get(i);
  leftJoin((Expression) path.getMetadata().getParent(), context.replacements.get(i));
  Expression index = ExpressionUtils.operation(Integer.class, JPQLOps.INDEX, alias);
  Object element = path.getMetadata().getElement();
  if (!(element instanceof Expression)) {
    element = ConstantImpl.create(element);
  }
  Predicate condition = ExpressionUtils.eq(index, (Expression) element);
  if (where) {
    super.where(condition);
  } else {
    super.having(condition);
  }
}

代码示例来源：origin: com.querydsl/querydsl-jpa

@SuppressWarnings("unchecked")
@Override
public Expression<?> visit(Path<?> expr, @Nullable Void context) {
  expr = (Path<?>) super.visit(expr, null);
  PathMetadata pathMetadata = expr.getMetadata();
  if (pathMetadata.getPathType() == PathType.LISTVALUE
      || pathMetadata.getPathType() == PathType.LISTVALUE_CONSTANT) {
    Path<?> replacement = replacements.get(expr);
    if (replacement == null) {
      // join parent as path123 on index(path123) = ...
      Path parent = shorten(pathMetadata.getParent(), true);
      replacement = ExpressionUtils.path(expr.getType(),
          ExpressionUtils.createRootVariable(parent, replacements.size()));
      metadata.addJoin(JoinType.LEFTJOIN, ExpressionUtils.as(parent, replacement));
      metadata.addJoinCondition(ExpressionUtils.eq(
          (Expression) Expressions.operation(Integer.class, JPQLOps.INDEX, replacement),
          ExpressionUtils.toExpression(pathMetadata.getElement())));
      replacements.put(expr, replacement);
    }
    return replacement;
  } else {
    return super.visit(expr, context);
  }
}

代码示例来源：origin: com.querydsl/querydsl-jpa

@SuppressWarnings("unchecked")
@Override
public Expression<?> visit(Path<?> expr, @Nullable Void context) {
  expr = (Path<?>) super.visit(expr, null);
  PathMetadata pathMetadata = expr.getMetadata();
  if (pathMetadata.getPathType() == PathType.MAPVALUE
   || pathMetadata.getPathType() == PathType.MAPVALUE_CONSTANT) {
    Path<?> replacement = replacements.get(expr);
    if (replacement == null) {
      // join parent as path123 on key(path123) = ...
      Path parent = shorten(pathMetadata.getParent(), true);
      ParameterizedExpression parExpr = (ParameterizedExpression) pathMetadata.getParent();
      replacement = ExpressionUtils.path(parExpr.getParameter(1),
          ExpressionUtils.createRootVariable(parent, replacements.size()));
      metadata.addJoin(JoinType.LEFTJOIN, ExpressionUtils.as(parent, replacement));
      metadata.addJoinCondition(ExpressionUtils.eq(
          Expressions.operation(parExpr.getParameter(0), JPQLOps.KEY, replacement),
          ExpressionUtils.toExpression(pathMetadata.getElement())));
      replacements.put(expr, replacement);
    }
    return replacement;
  } else {
    return super.visit(expr, context);
  }
}

代码示例来源：origin: com.querydsl/querydsl-jpa

@SuppressWarnings("unchecked")
@Override
public Expression<?> visit(Operation<?> expr, @Nullable Void context) {
  if (expr.getOperator() == Ops.CONTAINS_KEY) {
    ParameterizedExpression map = (ParameterizedExpression<?>) expr.getArg(0);
    Expression key = expr.getArg(1);
    Path replacement = ExpressionUtils.path(map.getParameter(1),
        ExpressionUtils.createRootVariable((Path<?>) map, Math.abs(expr.hashCode())));
    metadata.addJoin(JoinType.LEFTJOIN, ExpressionUtils.as(map, replacement));
    metadata.addJoinCondition(ExpressionUtils.eq(
        Expressions.operation(map.getParameter(0), JPQLOps.KEY, replacement),
        key));
    return ExpressionUtils.isNotNull(replacement);
  } else if (expr.getOperator() == Ops.CONTAINS_VALUE) {
    ParameterizedExpression<?> map = (ParameterizedExpression<?>) expr.getArg(0);
    Expression<?> value = expr.getArg(1);
    return Expressions.predicate(JPQLOps.MEMBER_OF, value, map);
  } else {
    return super.visit(expr, context);
  }
}

代码示例来源：origin: com.querydsl/querydsl-jpa

@SuppressWarnings("unchecked")
@Override
protected Predicate exists(Context c, Predicate condition) {
  JPAQueryMixin<?> query = new JPAQueryMixin<Object>();
  query.setProjection(Expressions.ONE);
  for (int i = 0; i < c.paths.size(); i++) {
    Path<?> child = c.paths.get(i).getMetadata().getParent();
    EntityPath<Object> replacement = (EntityPath<Object>) c.replacements.get(i);
    if (c.paths.get(i).getType().isAnnotationPresent(Entity.class)) {
      query.addJoin(i == 0 ? JoinType.DEFAULT : JoinType.INNERJOIN, Expressions.as(
          Expressions.listPath((Class) c.paths.get(i).getType(), SimplePath.class,
              child.getMetadata()), replacement));
    } else {
      // join via parent
      Path<?> parent = child.getMetadata().getParent();
      EntityPathBase<Object> newParent = new EntityPathBase<Object>(parent.getType(),
          ExpressionUtils.createRootVariable(parent, Math.abs(condition.hashCode())));
      EntityPath<Object> newChild = new EntityPathBase<Object>(child.getType(),
          PathMetadataFactory.forProperty(newParent, child.getMetadata().getName()));
      query.from(newParent);
      query.addJoin(JoinType.INNERJOIN, Expressions.as(newChild, replacement));
      query.where(ExpressionUtils.eq(newParent, parent));
    }
  }
  c.clear();
  query.where(condition);
  return ExpressionUtils.predicate(Ops.EXISTS, asExpression(query.getMetadata()));
}

代码示例来源：origin: com.thinkbiganalytics.kylo/kylo-operational-metadata-jpa

@Override
public Page<? extends ServiceLevelAssessment> findAll(String filter, Pageable pageable) {
  QJpaServiceLevelAssessment serviceLevelAssessment = QJpaServiceLevelAssessment.jpaServiceLevelAssessment;
  pageable = CommonFilterTranslations.resolveSortFilters(serviceLevelAssessment, pageable);
  QJpaObligationAssessment obligationAssessment = new QJpaObligationAssessment("obligationAssessment");
  QJpaMetricAssessment metricAssessment = new QJpaMetricAssessment("metricAssessment");
  QJpaServiceLevelAgreementDescription serviceLevelAgreementDescription = new QJpaServiceLevelAgreementDescription("slaDescription");
  QJpaOpsManagerFeed feed = new QJpaOpsManagerFeed("feed");
  BooleanBuilder assessmentPredicate = GenericQueryDslFilter.buildFilter(serviceLevelAssessment, filter);
  BooleanBuilder feedPredicate = GenericQueryDslFilter.buildFilter(feed, filter);
  boolean invalidQuery = false;
  //if there is not predicate found for the supplied 'filter' then fail the query
  if (StringUtils.isNotBlank(filter) && (!assessmentPredicate.hasValue() && !feedPredicate.hasValue())) {
    invalidQuery = true;
  }
  BooleanBuilder predicate = assessmentPredicate.and(feedPredicate);
  if (invalidQuery) {
    predicate.and(ExpressionUtils.eq(ConstantImpl.create("1"), ConstantImpl.create("2")));
  }
  predicate.and(feed.isNull().or(feed.isNotNull().and(FeedAclIndexQueryAugmentor.generateExistsExpression(feed.id, accessController.isEntityAccessControlled()))));
  return findAllWithFetch(serviceLevelAssessment,
              predicate,
              true,
              pageable,
              QueryDslFetchJoin.innerJoin(serviceLevelAssessment.serviceLevelAgreementDescription, serviceLevelAgreementDescription),
              QueryDslFetchJoin.leftJoin(serviceLevelAgreementDescription.feeds, feed),
              QueryDslFetchJoin.leftJoin(serviceLevelAssessment.obligationAssessments, obligationAssessment),
              QueryDslFetchJoin.leftJoin(obligationAssessment.metricAssessments, metricAssessment));
}