对于Web应用程序,我想构建一个WHERE子句并将其提交给服务器.在那里,我将它附加到查询.该条款将是类似的
LASTNAME LIKE 'Pep%' AND (DOB BETWEEN '19600101' AND '19601231 OR SALARY<35000)
在将该子句提交给SQL Server之前,是否可以提出一个正则表达式来验证该子句？
(是的,当然,我想要ORDER子句的正则表达式)
我想在一个select语句中替换两件事.现在我可以一次替换一个角色.但是根据我的要求,我需要在一个语句中替换两个东西.我想用零替换一个特殊字符,另一个是将这些数据存储在多行中.我想在一行中获取这些数据.
select replace(message,chr(ACII_Value),0)
from my_table -- I can replace special character by zero using this.
select (message,chr(10),' ')
from my_table -- I can put all data in single line using this.
现在我想在一个select语句中执行此操作.
使用SQL查询,我们如何获得2列的输出,第一列是以asc顺序排序的列,第二列是顺序desc,两者都是相同的列.
例如:
emp table:
empid
1
5
9
4
查询输出应该是
empid_1 empid_2
1 9
4 5
5 4
9 1
OP到目前为止尝试了什么
WITH emp1
AS (SELECT ROWNUM a,
empno
FROM (SELECT empno
FROM emp
ORDER BY 1 ASC)),
emp2
AS (SELECT ROWNUM b,
empno
FROM (SELECT empno
FROM emp
ORDER BY 1 DESC))
SELECT emp1.empno,
emp2.empno
FROM emp1,
emp2
WHERE emp1.a = emp2.b;
我正在使用RStudio并且一直在尝试使用rPython包为我做一些电子邮件处理.这涉及解压缩一些电子邮件附件,因此我需要使用比2.7更新的Python版本.
我在ubuntu上,所以我在bash脚本中设置了环境变量,我可以看到它有效:
庆典
alias python=python3
export RPYTHON_PYTHON_VERSION=3
命令行
echo $RPYTHON_PYTHON_VERSION
3
然而,当我在RStudio中安装rPython时,它说:
将包安装到'/home/richardc/R/x86_64-pc-linux-gnu-library/3.1'(未指定'lib')尝试URL'http://cran.rstudio.com/src/contrib/rPython_0 . 0-5.tar.gz '内容类型'应用程序/ x-gzip'长度37109字节(36 Kb)
下载了36 Kb
因此,尽管python --version返回3.4并设置环境变量,它默认为2.7
我希望我有一些直截了当的东西.
尽管阅读了书籍和文章,但我无法找到下面的具体答案.
OLAP和OLTP的最小和最大标准化程度应该是多少？
我认为,OLTP的最小值是第3范式,OLAP的最大值是第2范式.
我们可以请详细说明以补充答案吗？
olap database-design oltp normalization database-normalization
你好,我有一个这样的表:
|user_name|pw|register_date|last_time_entered
我想得到last_seen_date - register_date <7的所有行
我不知道怎么写这个查询我想到这样的事情
SELECT * FROM workoutlog_1.personal
WHERE DATEDIFF(day, workoutlog_1.personal.register_date, workoutlog_1.personal.last_time_entered) < 7;
但我得到这个错误:
Error Code: 1582. Incorrect parameter count in the call to native function 'DATEDIFF'
谢谢你的帮助.
我很难理解这一点.我认为,我可以编写一个返回代码比较,如下所示.哪个更好？为什么会这样？
RC=$?
if [[ $RC == '0' ]]; then
if [ $RC -eq '0' ]; then
if [ $RC == '0' ]; then
if [ "$RC" == "0" ]; then
if [ "$RC" -eq "0" ]; then
if [[ "$RC" == "0" ]]; then
if (( "$RC" == "0" )); then
if ( "$RC" == "0" ); then
if (( $RC == 0 )); then
if ( $RC == 0 ); then
还有一些......
如果RC="A"- 字符串怎么办？
我现在正在测试 hyperledger/fabric/core/comm/testdata/certs/generate.go 以获得 ECDSA prime256v1 证书（Org1-cert.pem）和私钥（Org1-key.pem）。我想使用 openssl 命令行来测试 Org1-cert.pem 是否对 Org1-key.pem 进行数学运算，但不知道如何？任何帮助表示赞赏。我已经使用了该命令，但结果不匹配。
# openssl x509 -pubkey -in Org1-cert.pem -noout | openssl md5
（标准输入）= 4f8782bbec9d258553f0c0c7c6879fef
# openssl pkey -pubout -in Org1-key.pem | openssl md5
（标准输入）= 98c3ec3c2971648f2721915ff7e80479
更多关于 Org1-cert.pem 和 Org1-key.pem 的信息如下：
# openssl x509 -in Org1-cert.pem -text -noout
Certificate:
Data:
Version: 3 (0x2)
Serial Number:
50:0a:7a:e4:31:6e:1b:57:68:48:26:d7:a0:c5:9c:da
Signature Algorithm: ecdsa-with-SHA256
Issuer: C = US, ST = California, L = San Francisco, O = Org1, CN = Org1
Validity
Not Before: Nov 13 …以下两个查询给出相同的结果.只是想知道哪一个在性能方面更好.
查询1:
SELECT N.*
FROM NOTIFICATIONS N
JOIN NOTIFICATION_COMPANY_GROUPS NCG
ON ( N.COMPANY_ID = NCG.COMPANY_ID
AND N.ID = NCG.NOTIFICATION_ID )
JOIN COMPANY_USER_GROUPS CUG
ON ( N.COMPANY_ID = CUG.COMPANY_ID
AND CUG.COMPANY_GROUP_ID = NCG.COMPANY_GROUP_ID )
JOIN NOTIFICATION_PROPERTIES NP ON ( N.COMPANY_ID = NP.COMPANY_ID )
JOIN COMPANY_USER_PROPERTIES CUP
ON ( N.COMPANY_ID = CUP.COMPANY_ID
AND CUP.PROPERTY_ID = NP.PROPERTY_ID )
WHERE N.COMPANY_ID = 2138
AND CUG.COMPANY_USER_ID = 41422
AND CUP.COMPANY_USER_ID = 41422;
查询2:
SELECT N.*
FROM NOTIFICATIONS N
JOIN NOTIFICATION_COMPANY_GROUPS NCG
ON ( N.COMPANY_ID = …有人可以看看我的查询。当我尝试取消对任何注释字段的注释时，oracle 会抛出错误。
SELECT *
FROM (
SELECT ratfac.rating_id,
ratfac.label_en,
ratfac.ratingmodel_factor_id,
ratfac.weight,
ratfac.rating_calculated,
ratfac.rating,
ratfac.rating_adjusted,
ratfac.override_comment,
ratfac.rating_override,
ratfac.notch_value,
ratfac.notch_value_calculated,
ratfac.notch_value_adjusted,
ratfac.score,
ratfac.score_calculated,
ratfac.score_adjusted,
ratfac.factor_comment
FROM vw_ratingfactor ratfac ) pivot ( min(ratingmodel_factor_id) ratingmodel_factor_id, min(weight) weight, min(rating_calculated) rating_calculated, min(rating) rating,
--MAX(RATING_ADJUSTED) as RATING_ADJ,
min(override_comment) override_comment, min(rating_override) rating_override, min(notch_value) notch_value,
--MIN(NOTCH_VALUE_CALCULATED) NOTCH_VALUE_CALCULATED,
--MIN(NOTCH_VALUE_ADJUSTED) NOTCH_VALUE_ADJUSTED,
min(score) score, min(score_calculated) score_calculated, min(score_adjusted) score_adjusted, min(factor_comment) factor_comment FOR label_en IN ('Market'
|| chr(38)
||'Competitiveness' AS marketcompetitiveness,
'Industry' AS industry,
'Company Strategy and Management' AS company_stratergy_mgmt,
'Financial Performance' AS financial_performance, …