Need Help in updating mysql table - mysql

Question

I have a table x with the below fields,
n_i int(10) NOT NULL,
n_m longtext,
n_t varchar(255) DEFAULT NULL,
n_s varchar(50) DEFAULT NULL,
n_c int(10) DEFAULT NULL,
n_d datetime DEFAULT NULL
Data:
1, ABC has kept Hold rating on John Inc for target of $ 125 over a 12 month horizon from the current market price of $ 101., Hold John Inc for target of $ 125: ABC, ABC PCG, 1, 1/27/2006 22:55
2, RB Research has kept Buy rating on Johnson (New York) Inc for target of $ 80 over a 12 month horizon from the current market price of $ 64., Buy Johnson (New York) Inc for target of $ 80: RB Research, RB Research, 1, 1/27/2006 23:03
3, XYZ Research has kept Buy rating on John & John Manufacturing (USA) Inc, a subsidiary of John & John Inc for target of $ 340 from the current market price of $ 270., Buy John & John Manufacturing (USA) Inc for target of Rs.340: XYZ Research, XYZ Research, 1, 1/27/2006 23:06
4, ABCDE Research has upgraded Johnson (New York) Inc to Buy with a target of $ 1000 from the current market price of $ 750., Buy Johnson (New York) Inc for target of $ 1000: ABCDE Research, ABCDE Research, 1, 1/27/2006 23:10
5, JKL Private Client Research has kept Buy rating on John2 Inc, parent company of John & John Manufacturing (USA) Inc with a target price of $ 295 from the current market price of $ 276., Buy John2 Inc for target of $ 295: JKL Private Client Research, JKL Private CLient Research, 1, 1/27/2006 23:12
I would like to create the below table y with data from above table plus a new field n_sy. The search criteria is a string say, BSSN which will be taken from table z and searched in fields n_t and n_m of table x and if found field n_sy in table y would be updated with corresponding field data "BSIS" from table z. Also, the field "n_sy" should be able to hold more than one value. :-(
n_i int(10) NOT NULL,
n_m longtext,
n_t varchar(255) DEFAULT NULL,
n_s varchar(50) DEFAULT NULL,
n_c int(10) DEFAULT NULL,
n_d datetime DEFAULT NULL,
n_sy text NOT NULL
Data:
1, ABC has kept Hold rating on John Inc for target of $ 125 over a 12 month horizon from the current market price of $ 101., Hold John Inc for target of $ 125: ABC, ABC PCG, 1, 1/27/2006 22:55, ABCD12345J
2, RB Research has kept Buy rating on Johnson (New York) Inc for target of $ 80 over a 12 month horizon from the current market price of $ 64., Buy Johnson (New York) Inc for target of $ 80: RB Research, RB Research, 1, 1/27/2006 23:03, ABCD34567L
3, XYZ Research has kept Buy rating on John & John Manufacturing (USA) Inc, a subsidiary of John & John Inc for target of $ 340 from the current market price of $ 270., Buy John & John Manufacturing (USA) Inc for target of Rs.340: XYZ Research, XYZ Research, 1, 1/27/2006 23:06, "ABCD56789A, ABCD45678M"
4, ABCDE Research has upgraded Johnson (New York) Inc to Buy with a target of $ 1000 from the current market price of $ 750., Buy Johnson (New York) Inc for target of $ 1000: ABCDE Research, ABCDE Research, 1, 1/27/2006 23:10, ABCD34567L
5, JKL Private Client Research has kept Buy rating on John2 Inc, parent company of Johnson (New York) Inc with a target price of $ 295 from the current market price of $ 276., Buy John2 Inc for target of $ 295: JKL Private Client Research, JKL Private CLient Research, 1, 1/27/2006 23:12, "ABCD23456K, ABCD34567L"
Table z
`BSCe` double DEFAULT NULL,
`BSSI` text,
`BSSN` text,
`BSSt` text,
`BSGr` text,
`BSFV` int(11) DEFAULT NULL,
`BSIS` text,
`BSIn` text,
`BSInst` text,
`NSSy` text,
`NSSc` text,
`NSSer` text,
`NSDOL` text,
`NSPUV` int(4) DEFAULT NULL,
`NSMktL` int(3) DEFAULT NULL,
`NSIS` text,
`NSEFV` int(11) DEFAULT NULL
12345, ABCD, John Inc, A, B, 10, ABCD12345J, Mine, E, J12345, John, T, 10-Oct-2019, 10, 1, ABCD12345J, 10
12346, XYZ, John2 Inc, A, B, 10, ABCD23456K, Iron, E, J12346, John2, T, 11-Jan-2020, 10, 1, ABCD23456K, 10
12347, JKL, Johnson (New York) Inc, A, B, 10, ABCD34567L, Electricty, E, J12347, John3, T, 7-Dec-2019, 10, 1, ABCD34567L, 10
12348, IJK, John & John Inc, A, B, 10, ABCD45678M, Mine, E, J12348, John & John, T, 19-Apr-2019, 10, 1, ABCD45678M, 10
12349, EFGH, John & John Manufacturing (USA) Inc, A, B, 10, ABCD56789A, IT, E, J12349, John & John Manufacturing Inc, T, 29-May-2019, 10, 1, ABCD56789A, 10
Looking for your help, as the MYSQL table is fairly large.

Answer 1

Use below query,
Creates the table with structure of x
create table y as select * from table x;
Adds column column n_sy
alter table y add n_sy text NOT NULL;
Updates BSSN from z to n_sy in y
update y
inner join z
on (z.BSSN = y.n_t)
set y.n_sy = z.BSIS;
Updates BSSN from z to n_sy in y to hold more than one value
update y
inner join z
on (z.BSSN = y.n_m)
set y.n_sy = y.n_sy || ',' || z.BSIS;