MySQL Data Types (Version 8.0) In MySQL there are three main data types: string, numeric, and date and time. String Data Types Data typeDescription CHAR(size)A FIXED length string (can contain letters, numbers, and special characters). Thesizeparameter specifies the column length in characters...
, c.DATA_TYPE columnType -- 字段类型 varchar之类的 , c.DATA_LENGTH columnLength -- 以字符为单位的最大长度 , -1 columnOctetLength -- 以字节为单位的最大长度 , c.DATA_PRECISION columnNumberPrecision -- 数字类型整数位长度 , c.DATA_SCALE columnNumberScale -- 数字小数位长度 , c.DATA_DEFAU...
id: This column is of the DECIMAL data type. DECIMAL is used for numeric data with a fixed precision and scale. It is designated as the PRIMARY KEY for the table, implying that each value in this column must be unique and not null. col1: This column is of the BINARY data type with...
The syntax for SQL Data Types is: CREATETABLEtable_name ( column1_name datatype1, column2_name datatype2, column3_name datatype3, ... ); Here, column1_name,column2_name,column3_name,...are the names of the columns datatype1,datatype2,datatype3,...are the data types such asINT...
SQLINTEGER cbSQLDataType; SQLINTEGER cbOrdinalPosition; int main() { SQLHENV henv; SQLHDBC hdbc; SQLHSTMT hstmt = 0; SQLRETURN retcode; char* pdsn = "MySQL8030"; char* puid = "root"; char* ppwd = "databasepassword"; char* tablename = "testcolumntypes"; ...
Accompanying each C/C++ data type is the corresponding defined type from sqludf.h. Table 1. SQL Data Types Mapped to C/C++ Declarations SQL Column TypeC/C++ Data TypeSQL Column Type Description SMALLINT sqlint16 SQLUDF_SMALLINT 16-bit signed integer INTEGER sqlint32 SQLUDF_INTEGER 32-bit ...
ALTER TABLE 管理 COLUMN ALTER TABLE 管理 PARTITION ALTER TABLE 或 CREATE TABLE .. MASK 子句 ALTER TABLE 或 CREATE TABLE .. ROW FILTER 條款 ALTER VIEW ALTER VOLUME COMMENT ON CREATE CATALOG CREATE CONNECTION CREATE DATABASE CREATE FUNCTION (SQL) CREATE FUNCTION (外部) 創建地點 CREATE MATERIALIZED...
int columnCount = rsmd.getColumnCount(); for (int i = 1; i <= columnCount; i++) { String s = rsmd.getColumnTypeName(i); System.out.println ("Column " + i + " is type " + s); } 8.4.2 带 IN 参数的 SQL 语句 在另一个可能的情况中,用户将发送带输入参数的 SQL 语句。这种情...
for (int i = 1; i <= columnCount; i++) { String s = rsmd.getColumnTypeName(i); System.out.println ("Column " + i + " is type " + s); } 8.4.2 带 IN 参数的 SQL 语句 在另一个可能的情况中,用户将发送带输入参数的 SQL 语句。这种情况下,用户通过调用PreparedStatement.setXXX方法...
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