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Server version: 5.7.19-log MySQL Community Server (GPL)

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mysql> create table test(txt text);
Query OK, 0 rows affected (0.20 sec)

mysql> insert into test select '{"ID":250,"TYPER":1,"BRAND":"SNR","MODEL":"S2960-48G","PORT":48,"MANAGED":1,"FDBTYPER":3}';
Query OK, 1 row affected (0.03 sec)
Records: 1  Duplicates: 0  Warnings: 0

mysql> insert into test select '{"ID":255,"TYPER":2,"BRAND":"qwe","MODEL":"S2960-12G","PORT":25,"MANAGED":0,"FDBTYPER":2}';
Query OK, 1 row affected (0.02 sec)
Records: 1  Duplicates: 0  Warnings: 0

mysql> SELECT JSON_EXTRACT(CAST(txt AS JSON), '$.BRAND') FROM test;
+--------------------------------------------+
| JSON_EXTRACT(CAST(txt AS JSON), '$.BRAND') |
+--------------------------------------------+
| "SNR"                                      |
| "qwe"                                      |
+--------------------------------------------+
2 rows in set (0.09 sec)

mysql> SELECT txt->"$.BRAND" FROM test;
+----------------+
| txt->"$.BRAND" |
+----------------+
| "SNR"          |
| "qwe"          |
+----------------+
2 rows in set (0.05 sec)

mysql>