Although primarily used for converting blobs (long varbinary, long varchar) to string, blob_to_string may also be used to convert from wide string, persistent XML (XPER) and string_output streams. If the data being converted is longer than maximum length of a string, blob_to_string will signal an error.
This function is equivalent to cast (x as varchar). Using cast is preferred.
Varchar contents of blob.
SQL> use Demo;
Done. -- 20 msec.
SQL> select blob_to_string (Description) from Categories;
callret
VARCHAR
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Soft drinks, coffees, teas, beers, and ales
Sweet and savory sauces, relishes, spreads, and seasonings
Desserts, candies, and sweet breads
Cheeses
Breads, crackers, pasta, and cereal
Prepared meats
Dried fruit and bean curd
Seaweed and fish
8 Rows. -- 37 msec.
SQL>