The binary Collation Compared to _bin Collations -> 3 mysql>  SELECT COERCIBILITY(’A’); -> 4 mysql>  SELECT COERCIBILITY(1000); -> 5 mysql>  SELECT COERCIBILITY(NULL); -> 6 For implicit conversion of a numeric or temporal value to a string, such as occurs for the argument  1  in the expression  CONCAT(1, ’abc’) , the result is a character (nonbinary) string that has a character set and collation determined by the  character_set_connection  and  collation_connection  system variables. See Section 12.3, “Type Conversion in Expression Evaluation” . This section describes how the  binary  collation for binary strings compares to  _bin  collations for nonbinary strings. Binary strings (as stored using the  BINARY ,  VARBINARY , and  BLOB  data types) have a character set and collation named  binary . Binary strings are sequences of bytes and the numeric values of those bytes determine comparison and sort order. See Section 10.10.8, “The Binary Character Set” . Nonbinary strings (as stored using the  CHAR ,  VARCHAR , and  TEXT  data types) have a character set and collation other than  binary . A given nonbinary character set can have several collations, each of which defines a particular comparison and sort order for the characters in the set. For most character sets, one of these is the binary collation, indicated by a  _bin  suffix in the collation name. For example, the binary collation for  utf8  and  latin1  is named  utf8_bin  and  latin1_bin , respectively.  utf8mb4  is an exception that has two binary collations,  utf8mb4_bin  and  utf8mb4_0900_bin ; see Section 10.10.1, “Unicode Character Sets” . The  binary  collation differs from  _bin  collations in several respects, discussed in the following sections: •The Unit for Comparison and Sorting •Character Set Conversion •Lettercase Conversion •Trailing Space Handling in Comparisons •Trailing Space Handling for Inserts and Retrievals Binary strings are sequences of bytes. For the  binary  collation, comparison and sorting are based on numeric byte values. Nonbinary strings are sequences of characters, which might be multibyte. Collations for nonbinary strings define an ordering of the character values for comparison and sorting. For  _bin collations, this ordering is based on numeric character code values, which is similar to ordering for binary strings except that character code values might be multibyte. A nonbinary string has a character set and is automatically converted to another character set in many cases, even when the string has a  _bin  collation: •When assigning column values to another column that has a different character set: UPDATE t1 SET utf8_bin_column=latin1_column; INSERT INTO t1 (latin1_column) SELECT utf8_bin_column FROM t2; 1956 Character Set Conversion The Unit for Comparison and Sorting 10.8.5 The binary Collation Compared to _bin Collations