Question

我有两个数据库，我想将其中一个//For building aggregation query def buildAgg(groups: Seq[String])(leafAggBuilder: () => AbstractAggregationDefinition): AbstractAggregationDefinition = { groups match { case x :: xs => aggregation.terms("termAgg").field(x).aggregations(buildAgg(xs)(leafAggBuilder)) case Nil => leafAggBuilder() } } //An example leaf aggregation builder def buildLeafAgg(aggFuncInfo: Pair[String, String])(): AbstractAggregationDefinition = { aggFuncInfo._1 match { case "avg" => aggregation.avg("aggFunc").field(aggFuncInfo._2) case "sum" => aggregation.sum("aggFunc").field(aggFuncInfo._2) case "cardinality" => aggregation.cardinality("aggFunc").field(aggFuncInfo._2) case _ => aggregation.count("aggFunc").field(aggFuncInfo._2) } } //For parsing aggregation def parseAgg[T](groups: Seq[String], agg: Aggregation, allGroups: Seq[String])(leafAggParser: (Seq[String], Aggregation) => Seq[T]): Seq[T] = { groups match { case x :: xs => { val groupAggs = agg.asInstanceOf[StringTerms].getBuckets.asScala.toList (for { groupAgg <- groupAggs aa = groupAgg.getAggregations.asList.asScala.head gkey = groupAgg.getKeyAsString gacc = allGroups :+ gkey } yield parseAgg(xs, aa, gacc)(leafAggParser)).flatten } case Nil => { leafAggParser(allGroups, agg) } } } //An example leaf aggregation parser def parseSimpleLeafAgg(allGroups: Seq[String], agg: Aggregation): Seq[GroupStats] = { val value = agg.asInstanceOf[InternalNumericMetricsAggregation.SingleValue].value() val groupId = allGroups.mkString(".") Seq(GroupStats(groupId, value)) } //Usage: Build Query and Parse result def groupStats(groupFields: Seq[String]): Seq[GroupStats] = { val resp = client.execute { def leafPlainAggBuilder = buildLeafAgg(("count", "V1")) _ search(esIndex).size(0).aggregations(buildAgg(groupFields)(leafPlainAggBuilder)) }.await //get the root aggregation val agg = resp.aggregations.asList().asScala.head def leafAggParser = parseSimpleLeafAgg _ val res = parseAgg(groupFields, agg, Seq())(leafAggParser) res }列与另一个列中的varchar50AllowNulls列进行比较。

我发现当我在varchar列中有一个值并且text列中有一个空字符串时，我对这些链接表的Access查询起作用。

但是当我在TextNotNull中有一个空字符串并且在text列中有一个值时，它不起作用。

我找不到任何似乎可以解决这个问题的话题。我可以要求开发人员将文本更改为varchar，但如果我可以使用SQL解析，我认为最好。

我的猜测是我需要施放或修剪，但我的努力没有成功。

varchar

Answer 1

以下WHERE子句的逻辑是，当可空VARCHAR列的不等于非可空TEXT时，您要删除记录柱。如果Varchar50AllowNulls 不 NULL，则使用<>的原始条件已经在检查此情况。但是，当Varchar50AllowNulls NULL时，<>将不起作用，因为将NULL的任何值进行比较是未知的。相反，由于TextNotAllowNulls不能NULL，因此无论Varchar50AllowNulls是NULL，您都希望删除此记录，而不管TEXT列的值是什么。< / p>

SELECT A.EQNUM,
       A.[Varchar50AllowNulls],
       B.EQNUM,
       B.[TextNotAllowNulls]
FROM A
INNER JOIN B
    ON A.EQNUM = B.EQNUM
WHERE A.[Varchar50AllowNulls] <> B.[TextNotAllowNulls] OR
      A.[Varchar50AllowNulls] IS NULL

将SQL Varchar字段与SQL进行比较

1 个答案: