我想为我的数据库执行完整的数据库子字符串搜索。因此，如果一个领域有'你好世界，你和我正在寻找如何。结果应显示"你好世界[..呸��此外，我如何添加一个布尔变量，这是区分大小写或不区分大小写的。
我得到了以下代码，但仍然需要上层的东西来集成。有什么重新共性吗？
CREATE OR REPLACE FUNCTION search_columns(
needle text,
haystack_tables name[] default '{}',
haystack_schema name[] default '{public}'
)
RETURNS table(schemaname text, tablename text, columnname text, rowctid text)
AS $$
begin
FOR schemaname,tablename,columnname IN
SELECT c.table_schema,c.table_name,c.column_name
FROM information_schema.columns c
JOIN information_schema.tables t ON
(t.table_name=c.table_name AND t.table_schema=c.table_schema)
WHERE (c.table_name=ANY(haystack_tables) OR haystack_tables='{}')
AND c.table_schema=ANY(haystack_schema)
AND t.table_type='BASE TABLE'
LOOP
EXECUTE format('SELECT ctid FROM %I.%I WHERE cast(%I as text)=%L',
schemaname,
tablename,
columnname,
needle
) INTO rowctid;
IF rowctid is not null THEN
RETURN NEXT;
END IF;
END LOOP;
END;
$$ language plpgsql;
干杯
诚然
，我昨晚没有编译这个 - 如果我这样做了，我会看到错误。 你是对的，可选参数必须放在最后。 现在我确实有机会编译，这确实对我有用。
CREATE OR REPLACE FUNCTION search_columns(
needle text,
ignore_case boolean,
haystack_tables name[] default '{}',
haystack_schema name[] default '{public}'
)
RETURNS table(schemaname text, tablename text, columnname text, column_contents text)
AS $$
declare
like_function text := 'like';
nneedle text;
begin
nneedle := '%' || needle || '%';
FOR schemaname,tablename,columnname IN
SELECT c.table_schema,c.table_name,c.column_name
FROM information_schema.columns c
JOIN information_schema.tables t ON
(t.table_name=c.table_name AND t.table_schema=c.table_schema)
WHERE (c.table_name=ANY(haystack_tables) OR haystack_tables='{}')
AND c.table_schema=ANY(haystack_schema)
AND t.table_type='BASE TABLE'
LOOP
if ignore_case then
like_function := 'ilike';
end if;
execute format('SELECT %I FROM %I.%I WHERE cast(%I as text) %s %L',
columnname, schemaname, tablename, columnname, like_function, nneedle
) into column_contents;
IF column_contents is not null THEN
RETURN NEXT;
END IF;
END LOOP;
END;
$$ language plpgsql;
下面是一个用法示例：
select *
from search_columns('hambone', true, array['address_master'], array['sales']);
结果是：
schemaname tablename columnname column_contents
----------- ---------- ------------ ---------------------------
sales address_master address_desc Christopher "Hambone" Hamel
这就是我现在的做法：
package src;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Scanner;
import java.util.regex.Pattern;
/*
PATTERN MATCHING
*/
public class BigSearch {
public static void main(String[] args) {
try {
String keyword;
String schema = "public";
Boolean caseAware = true;
System.out.println("Insert the term we shall look for in the database.");
Scanner s = new Scanner(System.in);
keyword = s.nextLine();
System.out.println("Do you want the search to be case sensitve "
+ "n1 - case sensitive"
+ "n0 - case insensitive");
int caseAwareInt = s.nextInt();
while (caseAwareInt != 0 && caseAwareInt != 1) {
System.out.println("You need to enter 1 or 0. Enter again!");
caseAwareInt = s.nextInt();
}
if (caseAwareInt == 1) {
caseAware = true;
} else if (caseAwareInt == 0) {
caseAware = false;
}
System.out.println("Your search is now case ");
if (caseAware) {
System.out.println("sensitive!");
}
if (!caseAware) {
System.out.println("insensitive!");
}
String like = "";
if (caseAware) {
like = "LIKE";
} else {
like = "ILIKE";
}
Connection conn;
Connectivity connectivity = new Connectivity();
conn = connectivity.getConnection();
Statement stmt = conn.createStatement();
Statement stmt2 = conn.createStatement();
Statement stmt3 = conn.createStatement();
Statement stmt4 = conn.createStatement();
Statement stmt5 = conn.createStatement();
ResultSet rs = stmt.executeQuery("SELECT COUNT(*) FROM pg_catalog.pg_tables WHERE schemaname = '" + schema + "';");
ResultSet tablenames = stmt2.executeQuery("SELECT tablename FROM pg_catalog.pg_tables WHERE schemaname = '" + schema + "';");
rs.next();
int counttables = rs.getInt(1);
System.out.println("Tabellen im Schema: " + counttables);
int appearance = 0;
int diftables = 0;
for (int i = 0; i < counttables; i++) {
tablenames.next();
ResultSet columnnames = stmt3.executeQuery("SELECT column_name " +
"FROM information_schema.columns " +
"WHERE table_schema = '" + schema +
"' AND table_name = '" + tablenames.getString(1) +
"' AND data_type = 'character varying'");
ResultSet rss = stmt4.executeQuery("SELECT COUNT(*) " +
"FROM information_schema.columns " +
"WHERE table_schema = '" + schema +
"' AND table_name = '" + tablenames.getString(1) +
"' AND data_type = 'character varying'");
rss.next();
int countcolumns = rss.getInt (1);
System.out.println("Spalten in der Tabelle " + tablenames.getString(1) + ": " + countcolumns);
int count = 0;
for (int i2 = 0; i2 < countcolumns; i2++) {
columnnames.next();
columnnames.getString(1);
System.out.println("Spaltenname: " + columnnames.getString(1));
System.out.println("Tabelle: " + tablenames.getString(1));
ResultSet containsString;
containsString = stmt5.executeQuery("SELECT * "
+ "FROM " + tablenames.getString(1)
+ " WHERE " + columnnames.getString(1) + " " + like + " '%" + keyword + "%'");
while (containsString.next()) {
System.out.println(containsString.getString(1) + " -- contains your keyword");
appearance++;
count ++;
}
}
if (count > 0) {
diftables ++;
}
}
System.out.println("The keyword was found " + appearance + " times in " + diftables + " different tales.");
} catch (SQLException e) {
e.printStackTrace();
}
}
}