This is personal study note Copyright and original reference: https://www.youtube.com/watch?v=SLaQHVZXDiE&list=PLVsNizTWUw7HhYtI-4GGmlJ5yxNdwNI_X ================================================================================ ================================================================================ ================================================================================ ================================================================================ ================================================================================ ================================================================================ ================================================================================ ================================================================================ ELT: "second position one" is returned FIELD: "둘" is located in second position FIND_IN_SET: "둘" is located in second position by delimeter of , INSTR: "둘" is located in 3rd position from "하나둘셋" ================================================================================ ================================================================================ ================================================================================ ================================================================================ ================================================================================ ================================================================================ ================================================================================ ================================================================================ ================================================================================ "AA" 16 -> 2 100 10 -> 8 ================================================================================ ================================================================================ ================================================================================ number of selected rows number of updated rows