Substring function in SQLServer

No details. No expression string, binary string, text, image, column, or expression containing the substring (expression, start, length) parameter is used when operating SQL Server. Do not use expressions that contain aggregate functions. Start integer or an expression that can be implicitly converted to int.

No details. No expression string, binary string, text, image, column, or expression containing the substring (expression, start, length) parameter is used when operating SQL Server. Do not use expressions that contain aggregate functions. Start integer or an expression that can be implicitly converted to int.

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When operating SQL Server, the substring function SUBSTRING (expression, start, length) parameter expression string, binary string, text, image, column, or expression containing column is used. Do not use expressions that contain aggregate functions. The start integer or expression that can be implicitly converted to int, which indicates the start position of the stator string. Length Integer or an expression that can be implicitly converted to int, which refers to the length of the stator string (but the result is supplemented with a length returned, it depends on the expression length and start Settings !!!!!!!!!!!). Return value if expression is a supported character data type, the returned character data. If expression is a supported binary data type, binary data is returned. If start is set to 1, the substring must be added from the first character of the expression. If it is set to 1, it starts from the first character and counts, 2, 3, 4 .... similarly, select substring (ziduan, 200908) selects the first six characters of the field. For example, if is set to 0, select substring (ziduan,) is also executed) the result will be 20090. If you change to-1 and execute select substring (ziduan,-2009), the result will be and-2, -3 ,................. result of following substring ('20170101',-98765): 9 substring ('20160901', 98765) Result: 98 substring ('20160901', 98765) Result: 987