子串和 CHARINDEX答案

【问题标题】：SUBSTRING AND CHARINDEX子串和 CHARINDEX
【发布时间】：2016-05-08 22:52:50
【问题描述】：

我需要将“输液目标速率：###”放入它自己的字段中

我正在尝试这段代码 Substring(SummaryLine, CHARINDEX('Infusion: ',summaryline),+14) 但它不起作用。

, Initial Rate:  40, Goal Rate of Infusion:  0, to goal rate in 8 hours
, Initial Rate:  30, Goal Rate of Infusion:  0, to goal rate in 8 hours
, Initial Rate:  10, Goal Rate of Infusion:  10, to goal rate in 8 hours, HOLD FOR N/V
, Initial Rate:  40, Goal Rate of Infusion:  10, to goal rate in 8 hours
, Initial Rate:  40, Goal Rate of Infusion:  10, to goal rate in 8 hours
, Initial Rate:  100, Goal Rate of Infusion:  100, to goal rate in 8 hours
, Initial Rate:  15, Goal Rate of Infusion:  15, to goal rate in 8 hours
, Initial Rate:  40, Goal Rate of Infusion:  15, to goal rate in 8 hours

【问题讨论】：

显示您当前的代码，以便我们为您修复。
“它不工作”不是一个充分的问题描述。
Substring(SummaryLine, CHARINDEX('Infusion: ',summaryline),+14) AS NewSummaryField Infusion: 50, Infusion: 55, Infusion: 65, Infusion: 40, Infusion: 70, Infusion: 50 , 输液: 50, 输液: 40,
我得到“输液：50”，或输液：100（无逗号）
请编辑您的问题并添加此信息。您是否尝试过将“输液目标速率”放入 CHARINDEX 函数而不是“输液”，然后调整 14 的偏移量？

标签： sql sql-server

【解决方案1】：

SELECT
    SummaryLine,
    StartIdx,
    EndIdx,
    CONVERT(
        int,
        SUBSTRING( SummaryLine, StartIdx, EndIdx - StartIdx )
    ) AS InfusionRate
FROM (
    SELECT
        SummaryLine,
        StartIdx,
        CHARINDEX(',', summaryLine, StartIdx) AS EndIdx
    FROM (
        SELECT
            SummaryLine,
            CHARINDEX('Infusion:', SummaryLine) + 10 AS StartIdx,
        FROM
            SourceTable
    )
)

或单行：

SELECT
    CONVERT(
        int,
        SUBSTRING(
            SummaryLine,
            CHARINDEX('Infusion:', summaryLine) + 10,
            CHARINDEX(
                ',',
                SummaryLine,
                CHARINDEX('Infusion:', summaryLine) + 10
            )
        )
    )
FROM
    SourceTable

SQL 不允许您在单个 SELECT 语句中缓存或别名表达式结果，不幸的是 - 您需要使用子查询（第一个示例）或重复表达式（第二个示例）。

更新：我做了一些研究，你可以使用CROSS APPLY 计算一次StartIdx：

SELECT
    SummaryLine,
    CONVERT(
        int,
        SUBSTRING(
            SummaryLine,
            StartIdx,
            CHARINDEX(',', summaryLine, StartIdx) - StartIdx
        )
    ) AS InfusionRate
FROM
    SourceTable
    CROSS APPLY (
        SELECT CHARINDEX('Infusion:', summaryLine) + 10 AS StartIdx
    )

【讨论】：