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jpa @query 动态表名

news 来源：原创 2024/5/19 13:27:53

数据库分表

这里是用修改spring源码方式

#{#entityName} 默认为实体类@Entity注解的value值，会修改了其中实现

@Query(nativeQuery=true,value="delete from #{#entityName} where mobile=:#{#mobile}") int deleteByMobile(@Param("entityName")String entityName,@Param("mobile")String mobile);

主要修改类：（粗略,未验证）

org.springframework.data.jpa.repository.query.ExpressionBasedStringQuery

private static String renderQueryIfExpressionOrReturnQuery(String query, JpaQueryMethod method,
			SpelExpressionParser parser) {

		Assert.notNull(query, "query must not be null!");
		Assert.notNull(metadata, "metadata must not be null!");
		Assert.notNull(parser, "parser must not be null!");

		if (!containsExpression(query)) {
			return query;
		}
		//
        String entityName=method.getParameters()-->entityName

		StandardEvaluationContext evalContext = new StandardEvaluationContext();
		if(entityName==null){
            evalContext.setVariable(ENTITY_NAME, method.getEntityInformation().getEntityName());
        }else{
            evalContext.setVariable(ENTITY_NAME, entityName);
        }


		query = potentiallyQuoteExpressionsParameter(query);

		Expression expr = parser.parseExpression(query, ParserContext.TEMPLATE_EXPRESSION);

		String result = expr.getValue(evalContext, String.class);

		if (result == null) {
			return query;
		}

		return potentiallyUnquoteParameterExpressions(result);
	}

org.springframework.data.jpa.repository.query.AbstractStringBasedJpaQuery

public AbstractStringBasedJpaQuery(JpaQueryMethod method, EntityManager em, String queryString,
			QueryMethodEvaluationContextProvider evaluationContextProvider, SpelExpressionParser parser) {

		super(method, em);

		Assert.hasText(queryString, "Query string must not be null or empty!");
		Assert.notNull(evaluationContextProvider, "ExpressionEvaluationContextProvider must not be null!");
		Assert.notNull(parser, "Parser must not be null!");

		this.evaluationContextProvider = evaluationContextProvider;
		this.query = new ExpressionBasedStringQuery(queryString, method, parser);

		DeclaredQuery countQuery = query.deriveCountQuery(method.getCountQuery(), method.getCountQueryProjection());
		this.countQuery = ExpressionBasedStringQuery.from(countQuery, method, parser);

		this.parser = parser;

		Assert.isTrue(method.isNativeQuery() || !query.usesJdbcStyleParameters(),
				"JDBC style parameters (?) are not supported for JPA queries.");
	}