package util;import java.util.*; import java.util.regex.*; import java.io.*;public class UserTreeMap { public static void main(String args[]) throws IOException { BufferedReader buf = new BufferedReader(new FileReader("D:\\english.txt")); System.out.println("Read under this dir English.txt");
StringBuffer sbuf = new StringBuffer();// 缓冲字符串 String line = null; while ((line = buf.readLine()) != null) { sbuf.append(line);// 追加到缓冲字符串中 } buf.close();// 读取结束 Pattern expression = Pattern.compile("[a-zA-Z]+");// 定义正则表达式匹配单词 String string1 = sbuf.toString().toLowerCase();// 转换成小写 Matcher matcher = expression.matcher(string1);// 定义string1的匹配器 TreeMap myTreeMap = new TreeMap();// 创建树映射 存放键/值对 int n = 0;// 文章中单词总数 Object word = null;// 文章中的单词 Object num = null;// 出现的次数 while (matcher.find()) {// 是否匹配单词 word = matcher.group();// 得到一个单词-树映射的键 n++;// 单词数加1 if (myTreeMap.containsKey(word)) {// 如果包含该键,单词出现过 num = myTreeMap.get(word);// 得到单词出现的次数 Integer count = (Integer) num;// 强制转化 myTreeMap.put(word, new Integer(count.intValue() + 1)); } else { myTreeMap.put(word, new Integer(1));// 否则单词第一次出现,添加到映射中 } } System.out.println("统计分析如下:"); System.out.println("t 文章中单词总数" + n + "个"); System.out.println("具体的信息在当前目录的result.txt文件中"); BufferedWriter bufw = new BufferedWriter(new FileWriter("result.txt")); Iterator iter = myTreeMap.keySet().iterator();// 得到树映射键集合的迭代器 Object key = null; while (iter.hasNext()) {// 使用迭代器遍历树映射的键 key = iter.next(); bufw.write((String) key + ":" + myTreeMap.get(key));// 键/值写到文件中 bufw.newLine(); } bufw.write("english.txt中的单词总数" + n + "个"); bufw.newLine(); bufw.write("english.txt中不同单词" + myTreeMap.size() + "个"); bufw.close(); } }
有2个表 一个表B的记录多,最新表: id name tel address 0 a 123 asdf 1 b 456 asf 2 c 254 as 3 d 789 sadf 4 e 110 fs
另一个表A的记录少,是以前的表 id name tel address 0 peter 123 asdf 1 b 456 asf 2 c 254 as 现在我想删除A表中,B表也有的记录,MYSQL语句怎么写呢
java , mysql貌似你来错地方了.现在我想删除A表中,B表也有的记录,MYSQL语句怎么写呢delete from a where id in (select id from b)
[SQL] delete from a where id in (select id from b)[Err] 1064 - You have an error in your SQL syntax. Check the manual that corresponds to your MySQL server version for the right syntax to use near 'select id from b)' at line 4
delete from a where exists (select id from b where id=a.id)
[SQL] delete from a where exists (select id from b where id=a.id)[Err] 1064 - You have an error in your SQL syntax. Check the manual that corresponds to your MySQL server version for the right syntax to use near 'exists (select id from b where id=a.id
引用 3 楼 tangyu477 的回复: 有2个表 一个表B的记录多,最新表: id name tel address 0 a 123 asdf 1 b 456 asf 2 c 254 as 3 d 789 sadf 4 e 110 fs
另一个表A的记录少,是以前的表 id name tel address 0 peter 123 asdf 1 b 456 asf 2 c 254 as 现在我想删除A表中,B表也有的记录,MYSQL语句怎么写呢delete a from a,b where a.id=b.id
import java.util.regex.*;
import java.io.*;public class UserTreeMap { public static void main(String args[]) throws IOException {
BufferedReader buf = new BufferedReader(new FileReader("D:\\english.txt"));
System.out.println("Read under this dir English.txt");
StringBuffer sbuf = new StringBuffer();// 缓冲字符串
String line = null;
while ((line = buf.readLine()) != null) {
sbuf.append(line);// 追加到缓冲字符串中
}
buf.close();// 读取结束
Pattern expression = Pattern.compile("[a-zA-Z]+");// 定义正则表达式匹配单词
String string1 = sbuf.toString().toLowerCase();// 转换成小写
Matcher matcher = expression.matcher(string1);// 定义string1的匹配器
TreeMap myTreeMap = new TreeMap();// 创建树映射 存放键/值对
int n = 0;// 文章中单词总数
Object word = null;// 文章中的单词
Object num = null;// 出现的次数
while (matcher.find()) {// 是否匹配单词
word = matcher.group();// 得到一个单词-树映射的键
n++;// 单词数加1
if (myTreeMap.containsKey(word)) {// 如果包含该键,单词出现过
num = myTreeMap.get(word);// 得到单词出现的次数
Integer count = (Integer) num;// 强制转化
myTreeMap.put(word, new Integer(count.intValue() + 1));
} else {
myTreeMap.put(word, new Integer(1));// 否则单词第一次出现,添加到映射中
}
}
System.out.println("统计分析如下:");
System.out.println("t 文章中单词总数" + n + "个");
System.out.println("具体的信息在当前目录的result.txt文件中");
BufferedWriter bufw = new BufferedWriter(new FileWriter("result.txt"));
Iterator iter = myTreeMap.keySet().iterator();// 得到树映射键集合的迭代器
Object key = null;
while (iter.hasNext()) {// 使用迭代器遍历树映射的键
key = iter.next();
bufw.write((String) key + ":" + myTreeMap.get(key));// 键/值写到文件中
bufw.newLine();
}
bufw.write("english.txt中的单词总数" + n + "个");
bufw.newLine();
bufw.write("english.txt中不同单词" + myTreeMap.size() + "个");
bufw.close();
}
}
一个表B的记录多,最新表:
id name tel address
0 a 123 asdf
1 b 456 asf
2 c 254 as
3 d 789 sadf
4 e 110 fs
另一个表A的记录少,是以前的表
id name tel address
0 peter 123 asdf
1 b 456 asf
2 c 254 as 现在我想删除A表中,B表也有的记录,MYSQL语句怎么写呢
from a
where id
in (select id
from b)[Err] 1064 - You have an error in your SQL syntax. Check the manual that corresponds to your MySQL server version for the right syntax to use near 'select id
from b)' at line 4
[SQL] delete
from a
where
exists (select id
from b
where id=a.id)[Err] 1064 - You have an error in your SQL syntax. Check the manual that corresponds to your MySQL server version for the right syntax to use near 'exists (select id
from b
where id=a.id
有2个表
一个表B的记录多,最新表:
id name tel address
0 a 123 asdf
1 b 456 asf
2 c 254 as
3 d 789 sadf
4 e 110 fs
另一个表A的记录少,是以前的表
id name tel address
0 peter 123 asdf
1 b 456 asf
2 c 254 as
现在我想删除A表中,B表也有的记录,MYSQL语句怎么写呢delete a from a,b where a.id=b.id