检索与定位
本章主要展示关于检索与定位的代码参考，比如找出成员的位置、找出子序列的位置、找出满足条件的成员及其所在位置、从后向前找、找到第1个即停止/找出所有的、从第k个成员开始找、针对多个字段检索、对已经有序的序列（排列）使用二分法提高检索速度、针对检索后的结果汇总、对序表做过滤、使用主键值在排列（序表）中检索记录、找出最大值最小值所在记录和位置、找出最大值最小值所在记录和位置等。
找出成员的位置
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A |
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1 |
[3,2,1,5,1] |
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2 |
=A1.pos(1) |
3 |
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=A1.pos@a(1) |
[3,5] |
找出子序列的位置
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A |
B |
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1 |
[1,2,3,4,5] |
[4,5] |
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=A1.pos@c(B1) |
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4 |
找出满足条件的成员及其所在位置
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A |
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=demo.query("select EID,NAME, STATE, GENDER, BIRTHDAY,HIREDATE,DEPT, SALARY from EMPLOYEE") |
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2 |
=A1.select(GENDER=="M") |
找出所有成员 |
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3 |
=A1.pselect(GENDER=="M") |
找出第1个即停止，返回位置 |
从后向前找
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A |
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1 |
=demo.query("select EID, NAME,STATE, GENDER, BIRTHDAY,HIREDATE,DEPT,SALARY from EMPLOYEE") |
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2 |
=A1.select@z(GENDER=="M") |
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3 |
=A1.pselect@z(GENDER=="M") |
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找到第一个即停止 / 找出所有的
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A |
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1 |
=demo.query("select NAME,EVENT, SCORE from GYMSCORE") |
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=A1.pselect(EVENT:"UnevenBars") |
找出一个即停止 |
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=A1(A2).SCORE |
某项目的成绩 |
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=demo.query("select EID,NAME,STATE, GENDER,BIRTHDAY, HIREDATE,DEPT,SALARY from EMPLOYEE") |
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=A4.select(GENDER=="M") |
找出所有的成员 |
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=A4.select@1(GENDER=="M") |
找出第1个 |
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=A4.pselect@a(GENDER=="M") |
找出所有的位置 |
从第 k 个成员开始找
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A |
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1 |
=demo.query("select EID,NAME,STATE,GENDER,BIRTHDAY, HIREDATE,DEPT, SALARY from EMPLOYEE") |
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2 |
=A1.pselect(GENDER=="M",8) |
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针对多个字段检索
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A |
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1 |
=demo.query("select EID,NAME,STATE,GENDER,BIRTHDAY, HIREDATE, DEPT, SALARY from EMPLOYEE") |
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=A1.select(GENDER:"M",DEPT:"R&D") |
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=A1.pselect(GENDER:"M",DEPT:"R&D") |
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=A1.pselect@a(GENDER:"M",DEPT:"R&D") |
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对已经有序的序列（排列）使用二分法提高检索速度
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A |
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=demo.query("select * from EMPLOYEE order by GENDER,DEPT") |
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=A1.select@b(GENDER:"M",DEPT:"R&D") |
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=A1.pselect@b(GENDER:"M",DEPT:"R&D") |
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针对检索后的结果汇总
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A |
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=demo.query("select NAME,UNITPRICE,QUANTITY from RECEIPT") |
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2 |
=A1.select(NAME:"Apple").sum(UNITPRICE*QUANTITY) |
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对序表做过滤
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A |
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1 |
=demo.query("select EID,NAME,STATE,GENDER,BIRTHDAY, HIREDATE, DEPT, SALARY from EMPLOYEE") |
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=A1.select(SALARY<6300) |
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=A1.select(SALARY>5000) |
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使用主键值在排列（序表）中检索记录
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A |
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=demo.query("select * from SCORES") |
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=A1.keys(CLASS,STUDENTID) |
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=A1.pfind(["Class one",2]) |
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=A1(A3) |
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=A1.find(["Class one",2]) |
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找出最大值最小值所在记录和位置
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A |
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1 |
=demo.query("select EID,NAME,STATE,GENDER, BIRTHDAY,HIREDATE,DEPT,SALARY from EMPLOYEE ") |
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=A1.sort(HIREDATE) |
排序 |
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=A2.pmax(BIRTHDAY) |
最年轻员工所在位置 |
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=A2(to(A3-1)) |
更早入职的员工 |
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=A4.minp(BIRTHDAY).NAME |
其中最年长员工的名字 |
针对选出成员计算比上期
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A |
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=demo.query("select * from STOCKRECORDS") |
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=A1.pselect@a(CLOSING>10) |
找出超过10元的交易日的位置 |
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=A1.calc(A2, CLOSING/CLOSING[-1]-1) |
计算相应的涨幅 |
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=A2.new(A1(~).DATE:Date,A1(~).CLOSING:ClosingPrice,A3(#):Increase) |
/产生结果集 |
TOPN 所在位置
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A |
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=demo.query("select EID,NAME,STATE,GENDER, BIRTHDAY,HIREDATE,DEPT,SALARY from EMPLOYEE ") |
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=A1.ptop(5,BIRTHDAY) |
年龄最大的5个人的位置 |