ANSImakefiledemo ORACLEmakefiledemo

ANSI

makefile

dm02_ansi4: @echo ‘dm02_ansi4.pc start…’ proc iname=dm02_ansi4.pc oname=dm02_ansi4.c sqlcheck=full mode=ansi @echo ‘dm02_ansi4.pc ok…’ gcc dm02_ansi4.c -o dm02_ansi4 -I$ORACL{E}_{H}OME/precomp/public-L${ORACLE_HOME}/lib -lclntsh @echo ‘gcc ok…’

demo

/* sqlcheck=full */ /* mode=ansi */ #include <stdio.h> #include <string.h> #include <sqlca.h> /* 绑定变量值和 选择列表项值的最大长度 */ #define MAX_VAR_LEN 30 /* 定义选择列表项名的最大长度 */ #define MAX_NAME_LEN 80 /* 定义宿主变量 */ exec sql begin declare section; char *serverid = "c##scott/root"; char input_SqlStatements[100]; char current_date[20]; exec sql end declare section; void doerr(); int connet(); void process_input(); void process_output(); int main() { exec sql whenever sqlerror do doerr(); connet(); /* 分配输入描述区 输出描述区 */ exec sql allocate descriptor 'input_descriptor'; exec sql allocate descriptor 'output_descriptor'; for( ; ; ) { printf("\n请输入动态SQL语句(EXIT:退出):\n"); gets(input_SqlStatements); if(0 == strncmp(input_SqlStatements , "EXIT" , 4) || 0 == strncmp(input_SqlStatements , "exit" , 4)) break; /* 准备动态SQL语句 */ exec sql prepare mydynamicSql from :input_SqlStatements; /* 定义游标 */ exec sql declare mycursor cursor for mydynamicSql; /* 处理绑定变量 */ process_input(); /* 打开游标 * select语句：处理查询结果 * 其他SQL语句：执行 */ exec sql open mycursor using descriptor 'input_descriptor'; if(0 == strncmp(input_SqlStatements , "SELECT" , 6) , 0 == strncmp(input_SqlStatements , "select" , 6)) { process_output(); } /* 关闭游标 */ exec sql close mycursor; } /* 释放输入描述区和输出描述区 */ exec sql deallocate descriptor 'input_descriptor'; exec sql deallocate descriptor 'output_descriptor'; /* 提交事务，断开连接 */ exec sql commit work release; puts("谢谢使用ANSI动态SQL!\n"); return 0; } void doerr() { char szerrbuf[120]; size_t outputlen, inputlen = 120; unsigned int ret = 0; //出错时,可以把错误SQL语言给打印出来 EXEC SQL WHENEVER SQLERROR CONTINUE; ret = sqlgls(szerrbuf, &inputlen, &outputlen); printf("SQL:%.*s\n", inputlen, szerrbuf); printf("提示:%.*s\n", sqlca.sqlerrm.sqlerrml, sqlca.sqlerrm.sqlerrmc); EXEC SQL ROLLBACK WORK RELEASE; exit(1); } void process_input() { int i; /* 定义宿主变量 */ exec sql begin declare section; int input_count; int input_type ; int input_len; char input_buffer[MAX_VAR_LEN]; char name[MAX_NAME_LEN]; int occurs; exec sql end declare section; /* 绑定变量->输入描述区 */ exec sql describe input mydynamicSql using descriptor 'input_descriptor'; /* 取得绑定变量个数 */ exec sql get descriptor 'input_descriptor' :input_count = count; /* 循环处理绑定变量名 */ //屏蔽也行 具体没搞懂 input_count一直都是0 /* for(i = 0 ; i != input_count ; ++i) { occurs = i + 1; // 取得绑定变量名 exec sql get descriptor 'input_descriptor' value :occurs :name = name; printf("请输入%s的值：" , name); gets(input_buffer); // 以NULL结尾 input_len = strlen(input_buffer); input_buffer[input_len] = '\0'; // 设置绑定变量类型、长度和值 input_type = 1; exec sql set descriptor 'input_descriptor' value :occurs type = :input_type , length = :input_len , data = :input_buffer; } */ } void process_output() { int i; // 定义宿主变量 EXEC SQL BEGIN DECLARE SECTION ; int output_count; int output_type; int output_len; char output_buffer[MAX_VAR_LEN]; short output_indicator; char name[MAX_NAME_LEN]; int occurs; EXEC SQL END DECLARE SECTION ; // 选择列表项->输出描述区 exec sql describe output mydynamicSql using descriptor 'output_descriptor'; //取得选择列表项个数 exec sql get descriptor 'output_descriptor' :output_count = count; //循环处理选择列表项 （显示表头；设置显示。数据按照字符串格式） output_type = 12; //note //设置类型为变长字符串 //output_type = 1; //note for(i = 0 ; i != output_count ; ++i) { occurs = i + 1; output_len = MAX_VAR_LEN; // 设置选择列表项的类型和长度(设置每一列，按照varchar类型进行显示) exec sql set descriptor 'output_descriptor' value :occurs type = :output_type , length = :output_len; //取得选择列表项的名称并输出 exec sql get descriptor 'output_descriptor' value :occurs :name = name; //显示选择列表项名称 printf("\t%s" , name); } printf("\n"); // 提取数据完毕->退出循环 exec sql whenever not found do break; // 循环处理选择列表项数据 for( ; ; ) { // 行数据->输出描述区 exec sql fetch mycursor into descriptor 'output_descriptor'; // 循环处理每列数据 for(i = 0 ; i < output_count ; ++i) { occurs = i +1; // 取得列数据和指示变量值 exec sql get descriptor 'output_descriptor' VALUE :occurs :output_buffer = DATA , :output_indicator = INDICATOR; //输出列数据 if(-1 == output_indicator) printf("\t%s", " "); else printf("\t%s" , output_buffer); } printf("\n"); } } void connet() { int ret = 0; //连接数据库 EXEC SQL CONNECT:usrname IDENTIFIED BY:passwd USING:serverid ; if (sqlca.sqlcode != 0) { ret = sqlca.sqlcode; printf("sqlca.sqlcode: err:%d \n", sqlca.sqlcode); return ; } else { printf("connect ok...\n"); } }

ORACLE

makefile

dm03

all: dm03_oracle4

dm03_oracle4: @echo ‘dm03_oracle4.pc start…’ proc iname=dm03_oracle4.pc oname=dm03_oracle4.c @echo ‘dm03_oracle4.pc ok…’ gcc dm03_oracle4.c -o dm03_oracle4 -I$ORACL{E}_{H}OME/precomp/public-L${ORACLE_HOME}/lib -lclntsh @echo ‘gcc ok…’

clean: @rm dm03_oracle4 @rm dm03_oracle4.c

dm04 all: dm04_myselforacle4

dm04_myselforacle4: @echo ‘dm04_myselforacle4.pc start…’ proc iname=dm04_myselforacle4.pc oname=dm04_myselforacle4.c @echo ‘dm04_myselforacle4.pc ok…’ gcc dm04_myselforacle4.c -o dm04_myselforacle4 -I$ORACL{E}_{H}OME/precomp/public-L${ORACLE_HOME}/lib -lclntsh @echo ‘gcc ok…’

clean: @rm dm04_myselforacle4 @rm dm04_myselforacle4.c

demo

/******************************************************************* Sample Program 10: Dynamic SQL Method 4 This program connects you to ORACLE using your username and password, then prompts you for a SQL statement. You can enter any legal SQL statement. Use regular SQL syntax, not embedded SQL. Your statement will be processed. If it is a query, the rows fetched are displayed. You can enter multiline statements. The limit is 1023 characters. This sample program only processes up to MAX_ITEMS bind variables and MAX_ITEMS select-list items. MAX_ITEMS is #defined to be 40. *******************************************************************/ #include <stdio.h> #include <string.h> #include <setjmp.h> #include <sqlda.h> #include <stdlib.h> #include <sqlcpr.h> #define SQL_SINGLE_RCTX ((void *)0) /* Maximum number of select-list items or bind variables. */ #define MAX_ITEMS 40 /* Maximum lengths of the _names_ of the select-list items or indicator variables. */ #define MAX_VNAME_LEN 30 #define MAX_INAME_LEN 30 #ifndef NULL #define NULL 0 #endif /* Prototypes */ #if defined(__STDC__) void sql_error(void); int oracle_connect(void); int alloc_descriptors(int, int, int); int get_dyn_statement(void); void set_bind_variables(void); void process_select_list(void); void help(void); #else void sql_error(/*_ void _*/); int oracle_connect(/*_ void _*/); int alloc_descriptors(/*_ int, int, int _*/); int get_dyn_statement(/* void _*/); void set_bind_variables(/*_ void -*/); void process_select_list(/*_ void _*/); void help(/*_ void _*/); #endif char *dml_commands[] = {"SELECT", "select", "INSERT", "insert", "UPDATE", "update", "DELETE", "delete"}; EXEC SQL INCLUDE sqlda; EXEC SQL INCLUDE sqlca; EXEC SQL BEGIN DECLARE SECTION; char dyn_statement[1024]; EXEC SQL VAR dyn_statement IS STRING(1024); EXEC SQL END DECLARE SECTION; SQLDA *bind_dp; SQLDA *select_dp; /* Define a buffer to hold longjmp state info. */ jmp_buf jmp_continue; /* A global flag for the error routine. */ int parse_flag = 0; void main() { int i; /* Connect to the database. */ if (oracle_connect() != 0) exit(1); /* Allocate memory for the select and bind descriptors. */ if (alloc_descriptors(MAX_ITEMS, MAX_VNAME_LEN, MAX_INAME_LEN) != 0) exit(1); /* Process SQL statements. */ for (;;) { (void) setjmp(jmp_continue); /* Get the statement. Break on "exit". */ if (get_dyn_statement() != 0) break; /* Prepare the statement and declare a cursor. */ EXEC SQL WHENEVER SQLERROR DO sql_error(); parse_flag = 1; /* Set a flag for sql_error(). */ EXEC SQL PREPARE S FROM :dyn_statement; parse_flag = 0; /* Unset the flag. */ EXEC SQL DECLARE C CURSOR FOR S; /* Set the bind variables for any placeholders in the SQL statement. */ set_bind_variables(); /* Open the cursor and execute the statement. * If the statement is not a query (SELECT), the * statement processing is completed after the * OPEN. */ EXEC SQL OPEN C USING DESCRIPTOR bind_dp; /* Call the function that processes the select-list. * If the statement is not a query, this function * just returns, doing nothing. */ process_select_list(); /* Tell user how many rows processed. */ for (i = 0; i < 8; i++) { if (strncmp(dyn_statement, dml_commands[i], 6) == 0) { printf("\n\n%d row%c processed.\n", sqlca.sqlerrd[2], sqlca.sqlerrd[2] == 1 ? '\0' : 's'); break; } } } /* end of for(;;) statement-processing loop */ /* When done, free the memory allocated for pointers in the bind and select descriptors. */ for (i = 0; i < MAX_ITEMS; i++) { if (bind_dp->V[i] != (char *) 0) free(bind_dp->V[i]); free(bind_dp->I[i]); /* MAX_ITEMS were allocated. */ if (select_dp->V[i] != (char *) 0) free(select_dp->V[i]); free(select_dp->I[i]); /* MAX_ITEMS were allocated. */ } /* Free space used by the descriptors themselves. */ SQLSQLDAFree(SQL_SINGLE_RCTX, bind_dp); SQLSQLDAFree(SQL_SINGLE_RCTX, select_dp); EXEC SQL WHENEVER SQLERROR CONTINUE; /* Close the cursor. */ EXEC SQL CLOSE C; EXEC SQL COMMIT WORK RELEASE; puts("\nHave a good day!\n"); EXEC SQL WHENEVER SQLERROR DO sql_error(); return; } int oracle_connect() { EXEC SQL BEGIN DECLARE SECTION; VARCHAR username[128]; VARCHAR password[32]; EXEC SQL END DECLARE SECTION; printf("\nusername: "); fgets((char *) username.arr, sizeof username.arr, stdin); username.arr[strlen((char *) username.arr)-1] = '\0'; username.len = (unsigned short)strlen((char *) username.arr); printf("password: "); fgets((char *) password.arr, sizeof password.arr, stdin); password.arr[strlen((char *) password.arr) - 1] = '\0'; password.len = (unsigned short)strlen((char *) password.arr); EXEC SQL WHENEVER SQLERROR GOTO connect_error; EXEC SQL CONNECT :username IDENTIFIED BY :password; printf("\nConnected to ORACLE as user %s.\n", username.arr); return 0; connect_error: fprintf(stderr, "Cannot connect to ORACLE as user %s\n", username.arr); return -1; } /* * Allocate the BIND and SELECT descriptors using SQLSQLDAAlloc(). * Also allocate the pointers to indicator variables * in each descriptor. The pointers to the actual bind * variables and the select-list items are realloc'ed in * the set_bind_variables() or process_select_list() * routines. This routine allocates 1 byte for select_dp->V[i] * and bind_dp->V[i], so the realloc will work correctly. */ alloc_descriptors(size, max_vname_len, max_iname_len) int size; int max_vname_len; int max_iname_len; { int i; /* * The first SQLSQLDAAlloc parameter is the runtime context. * The second parameter determines the maximum number of * array elements in each variable in the descriptor. In * other words, it determines the maximum number of bind * variables or select-list items in the SQL statement. * * The third parameter determines the maximum length of * strings used to hold the names of select-list items * or placeholders. The maximum length of column * names in ORACLE is 30, but you can allocate more or less * as needed. * * The fourth parameter determines the maximum length of * strings used to hold the names of any indicator * variables. To follow ORACLE standards, the maximum * length of these should be 30. But, you can allocate * more or less as needed. */ if ((bind_dp = SQLSQLDAAlloc(SQL_SINGLE_RCTX, size, max_vname_len, max_iname_len)) == (SQLDA *) 0) { fprintf(stderr, "Cannot allocate memory for bind descriptor."); return -1; /* Have to exit in this case. */ } if ((select_dp = SQLSQLDAAlloc (SQL_SINGLE_RCTX, size, max_vname_len, max_iname_len)) == (SQLDA *) 0) { fprintf(stderr, "Cannot allocate memory for select descriptor."); return -1; } select_dp->N = MAX_ITEMS; /* Allocate the pointers to the indicator variables, and the actual data. */ for (i = 0; i < MAX_ITEMS; i++) { bind_dp->I[i] = (short *) malloc(sizeof (short)); select_dp->I[i] = (short *) malloc(sizeof(short)); bind_dp->V[i] = (char *) malloc(1); select_dp->V[i] = (char *) malloc(1); } return 0; } int get_dyn_statement() { char *cp, linebuf[256]; int iter, plsql; for (plsql = 0, iter = 1; ;) { if (iter == 1) { printf("\nSQL> "); dyn_statement[0] = '\0'; } fgets(linebuf, sizeof linebuf, stdin); cp = strrchr(linebuf, '\n'); if (cp && cp != linebuf) *cp = ' '; else if (cp == linebuf) continue; if ((strncmp(linebuf, "EXIT", 4) == 0) || (strncmp(linebuf, "exit", 4) == 0)) { return -1; } else if (linebuf[0] == '?' || (strncmp(linebuf, "HELP", 4) == 0) || (strncmp(linebuf, "help", 4) == 0)) { help(); iter = 1; continue; } if (strstr(linebuf, "BEGIN") || (strstr(linebuf, "begin"))) { plsql = 1; } strcat(dyn_statement, linebuf); if ((plsql && (cp = strrchr(dyn_statement, '/'))) || (!plsql && (cp = strrchr(dyn_statement, ';')))) { *cp = '\0'; break; } else { iter++; printf("%3d ", iter); } } return 0; } void set_bind_variables() { int i, n; char bind_var[64]; /* Describe any bind variables (input host variables) */ EXEC SQL WHENEVER SQLERROR DO sql_error(); bind_dp->N = MAX_ITEMS; /* Initialize count of array elements. */ EXEC SQL DESCRIBE BIND VARIABLES FOR S INTO bind_dp; /* If F is negative, there were more bind variables than originally allocated by SQLSQLDAAlloc(). */ if (bind_dp->F < 0) { printf ("\nToo many bind variables (%d), maximum is %d\n.", -bind_dp->F, MAX_ITEMS); return; } /* Set the maximum number of array elements in the descriptor to the number found. */ bind_dp->N = bind_dp->F; /* Get the value of each bind variable as a * character string. * * C[i] contains the length of the bind variable * name used in the SQL statement. * S[i] contains the actual name of the bind variable * used in the SQL statement. * * L[i] will contain the length of the data value * entered. * * V[i] will contain the address of the data value * entered. * * T[i] is always set to 1 because in this sample program * data values for all bind variables are entered * as character strings. * ORACLE converts to the table value from CHAR. * * I[i] will point to the indicator value, which is * set to -1 when the bind variable value is "null". */ for (i = 0; i < bind_dp->F; i++) { printf ("\nEnter value for bind variable %.*s: ", (int)bind_dp->C[i], bind_dp->S[i]); fgets(bind_var, sizeof bind_var, stdin); /* Get length and remove the new line character. */ n = strlen(bind_var) - 1; /* Set it in the descriptor. */ bind_dp->L[i] = n; /* (re-)allocate the buffer for the value. SQLSQLDAAlloc() reserves a pointer location for V[i] but does not allocate the full space for the pointer. */ bind_dp->V[i] = (char *) realloc(bind_dp->V[i], (bind_dp->L[i] + 1)); /* And copy it in. */ strncpy(bind_dp->V[i], bind_var, n); /* Set the indicator variable's value. */ if ((strncmp(bind_dp->V[i], "NULL", 4) == 0) || (strncmp(bind_dp->V[i], "null", 4) == 0)) *bind_dp->I[i] = -1; else *bind_dp->I[i] = 0; /* Set the bind datatype to 1 for CHAR. */ bind_dp->T[i] = 1; } return; } void process_select_list() { int i, null_ok, precision, scale; if ((strncmp(dyn_statement, "SELECT", 6) != 0) && (strncmp(dyn_statement, "select", 6) != 0)) { select_dp->F = 0; return; } /* If the SQL statement is a SELECT, describe the select-list items. The DESCRIBE function returns their names, datatypes, lengths (including precision and scale), and NULL/NOT NULL statuses. */ select_dp->N = MAX_ITEMS; EXEC SQL DESCRIBE SELECT LIST FOR S INTO select_dp; /* If F is negative, there were more select-list items than originally allocated by SQLSQLDAAlloc(). */ if (select_dp->F < 0) { printf ("\nToo many select-list items (%d), maximum is %d\n", -(select_dp->F), MAX_ITEMS); return; } /* Set the maximum number of array elements in the descriptor to the number found. */ select_dp->N = select_dp->F; /* Allocate storage for each select-list item. SQLNumberPrecV6() is used to extract precision and scale from the length (select_dp->L[i]). sqlcolumnNullCheck() is used to reset the high-order bit of the datatype and to check whether the column is NOT NULL. CHAR datatypes have length, but zero precision and scale. The length is defined at CREATE time. NUMBER datatypes have precision and scale only if defined at CREATE time. If the column definition was just NUMBER, the precision and scale are zero, and you must allocate the required maximum length. DATE datatypes return a length of 7 if the default format is used. This should be increased to 9 to store the actual date character string. If you use the TO_CHAR function, the maximum length could be 75, but will probably be less (you can see the effects of this in SQL*Plus). ROWID datatype always returns a fixed length of 18 if coerced to CHAR. LONG and LONG RAW datatypes return a length of 0 (zero), so you need to set a maximum. In this example, it is 240 characters. */ printf ("\n"); for (i = 0; i < select_dp->F; i++) { char title[MAX_VNAME_LEN]; /* Turn off high-order bit of datatype (in this example, it does not matter if the column is NOT NULL). */ SQLColumnNullCheck (0, (unsigned short *)&(select_dp->T[i]), (unsigned short *)&(select_dp->T[i]), &null_ok); switch (select_dp->T[i]) { case 1 : /* CHAR datatype: no change in length needed, except possibly for TO_CHAR conversions (not handled here). */ break; case 2 : /* NUMBER datatype: use SQLNumberPrecV6() to extract precision and scale. */ SQLNumberPrecV6( SQL_SINGLE_RCTX, (unsigned long *)&(select_dp->L[i]), &precision, &scale); /* Allow for maximum size of NUMBER. */ if (precision == 0) precision = 40; /* Also allow for decimal point and possible sign. */ /* convert NUMBER datatype to FLOAT if scale > 0, INT otherwise. */ if (scale > 0) select_dp->L[i] = sizeof(float); else select_dp->L[i] = sizeof(int); break; case 8 : /* LONG datatype */ select_dp->L[i] = 240; break; case 11 : /* ROWID datatype */ select_dp->L[i] = 18; break; case 12 : /* DATE datatype */ select_dp->L[i] = 9; break; case 23 : /* RAW datatype */ break; case 24 : /* LONG RAW datatype */ select_dp->L[i] = 240; break; } /* Allocate space for the select-list data values. SQLSQLDAAlloc() reserves a pointer location for V[i] but does not allocate the full space for the pointer. */ if (select_dp->T[i] != 2) select_dp->V[i] = (char *) realloc(select_dp->V[i], select_dp->L[i] + 1); else select_dp->V[i] = (char *) realloc(select_dp->V[i], select_dp->L[i]); /* Print column headings, right-justifying number column headings. */ /* Copy to temporary buffer in case name is null-terminated */ memset(title, ' ', MAX_VNAME_LEN); strncpy(title, select_dp->S[i], select_dp->C[i]); if (select_dp->T[i] == 2) if (scale > 0) printf ("%.*s ", select_dp->L[i]+3, title); else printf ("%.*s ", select_dp->L[i], title); else printf("%-.*s ", select_dp->L[i], title); /* Coerce ALL datatypes except for LONG RAW and NUMBER to character. */ if (select_dp->T[i] != 24 && select_dp->T[i] != 2) select_dp->T[i] = 1; /* Coerce the datatypes of NUMBERs to float or int depending on the scale. */ if (select_dp->T[i] == 2) if (scale > 0) select_dp->T[i] = 4; /* float */ else select_dp->T[i] = 3; /* int */ } printf ("\n\n"); /* FETCH each row selected and print the column values. */ EXEC SQL WHENEVER NOT FOUND GOTO end_select_loop; for (;;) { EXEC SQL FETCH C USING DESCRIPTOR select_dp; /* Since each variable returned has been coerced to a character string, int, or float very little processing is required here. This routine just prints out the values on the terminal. */ for (i = 0; i < select_dp->F; i++) { if (*select_dp->I[i] < 0) if (select_dp->T[i] == 4) printf ("%-*c ",(int)select_dp->L[i]+3, ' '); else printf ("%-*c ",(int)select_dp->L[i], ' '); else if (select_dp->T[i] == 3) /* int datatype */ printf ("%*d ", (int)select_dp->L[i], *(int *)select_dp->V[i]); else if (select_dp->T[i] == 4) /* float datatype */ printf ("%*.2f ", (int)select_dp->L[i], *(float *)select_dp->V[i]); else /* character string */ printf ("%-*.*s ", (int)select_dp->L[i], (int)select_dp->L[i], select_dp->V[i]); } printf ("\n"); } end_select_loop: return; } void help() { puts("\n\nEnter a SQL statement or a PL/SQL block at the SQL> prompt."); puts("Statements can be continued over several lines, except"); puts("within string literals."); puts("Terminate a SQL statement with a semicolon."); puts("Terminate a PL/SQL block (which can contain embedded semicolons)"); puts("with a slash (/)."); puts("Typing \"exit\" (no semicolon needed) exits the program."); puts("You typed \"?\" or \"help\" to get this message.\n\n"); } void sql_error() { /* ORACLE error handler */ printf ("\n\n%.70s\n",sqlca.sqlerrm.sqlerrmc); if (parse_flag) printf ("Parse error at character offset %d in SQL statement.\n", sqlca.sqlerrd[4]); EXEC SQL WHENEVER SQLERROR CONTINUE; EXEC SQL ROLLBACK WORK; longjmp(jmp_continue, 1); } dm04 /* 包含C头文件 */ #include <stdio.h> #include <string.h> #include <stdlib.h> #include <setjmp.h> #include <sqlcpr.h> /* 包含SQLDA和SQLCA结构 */ #include <sqlda.h> #include <sqlca.h> /* 定义绑定变量和选择列表项的最大个数 */ #define MAX_ITEMS 40 /* 定义绑定变量和选择列表项名称的最大长度 */ #define MAX_VNAME_LEN 30 /* 定义指示变量名称的最大长度 */ #define MAX_INAME_LEN 30 void connect(); void sql_error(); void alloc_descriptors(int , int , int); void dealloc_descriptors(); void set_bind_variables(); void process_select_list(); /* 定义绑定描述区和选择描述区 */ SQLDA* bind_dp; SQLDA* select_dp; /* 定义输入宿主变量：存放动态SQL语句 */ exec sql begin declare section; char sql_stat[100]; char current_date[20]; exec sql end declare section; int main() { /* 安装错误处理句柄 */ exec sql whenever sqlerror do sql_error(); /* 连接到数据库 */ connect2(); /* 分配绑定描述区和选择描述区 */ alloc_descriptors(MAX_ITEMS , MAX_VNAME_LEN , MAX_INAME_LEN); for( ; ; ) { printf("请输入动态SQL语句(exit:退出):"); gets(sql_stat); /* EXIT(exit):退出 */ if(0 == strncmp(sql_stat , "exit" , 4) || 0 == strncmp(sql_stat , "EXIT" , 4)) break; /* 准备动态SQL语句 */ exec sql prepare s from :sql_stat; /* 定义游标 */ exec sql declare c cursor for s; /* 出错，继续下一循环 */ if(0 != sqlca.sqlcode) continue; /* 设置绑定变量 */ set_bind_variables(); /* * 打开游标 * select语句：生成结果集 * 其他SQL语句：执行语句 */ exec sql open c using descriptor bind_dp; /* * select语句 */ if(0 == strncmp(sql_stat , "select" , 6) || 0 == strncmp(sql_stat , "SELECT" , 6)) { process_select_list(); } /* 关闭游标 */ exec sql close c; } /* 释放选择描述区和选择描述区 */ dealloc_descriptors(); /* 提交事务，断开连接 */ exec sql commit work release; puts("谢谢使用Oracle动态SQL方法四!\n"); return 0; } void connect2() { /* 定义宿主变量 */ exec sql begin declare section; char username[20] , password[20] , server[20]; exec sql end declare section; /* 输入用户名、口令和网络服务名 */ printf("username:"); gets(username); printf("password: "); gets(password); printf("server:"); gets(server); /* 连接到数据库 */ EXEC SQL CONNECT :username identified by :password using :server; } void sql_error() { /* 显示SQL错误信息 */ printf("%.*s\n" , sqlca.sqlerrm.sqlerrml , sqlca.sqlerrm.sqlerrmc); } //struct SQLDA { // ub4 // int N; // Descriptor size in number of entries // // text** // char **V; // Ptr to Arr of addresses of main variables // // ub4* // int *L; // Ptr to Arr of lengths of buffers // // sb2* // short *T; // Ptr to Arr of types of buffers // // sb2** // short **I; // Ptr to Arr of addresses of indicator vars // // sb4 // int F; // Number of variables found by DESCRIBE // // text** // char **S; // Ptr to Arr of variable name pointers // // ub2* // short *M; // Ptr to Arr of max lengths of var. names // // ub2* // short *C; // Ptr to Arr of current lengths of var. names // // text** // char **X; // Ptr to Arr of ind. var. name pointers // // ub2* // short *Y; // Ptr to Arr of max lengths of ind. var. names// // ub2* // short *Z; // Ptr to Arr of cur lengths of ind. var. names// // }; void alloc_descriptors(int size , int max_vname_len , int max_iname_len) { int i; /* 分配绑定描述区和选择描述区 */ bind_dp = SQLSQLDAAlloc(0 , size , MAX_VNAME_LEN , MAX_INAME_LEN); select_dp = SQLSQLDAAlloc(0 , size , MAX_VNAME_LEN , MAX_INAME_LEN); /* 为指示变量、绑定变量和选择列表项分配内存 */ for(i = 0 ; i != MAX_ITEMS ; ++i) { bind_dp->I[i] = (short*)malloc(sizeof(short)); select_dp->I[i] = (short*)malloc(sizeof(short)); bind_dp->V[i] = (char*)malloc(1); select_dp->V[i] = (char*)malloc(1); } } void dealloc_descriptors() { int i; /* 释放指示变量、绑定变量和选择列表项占用的内存 */ for(i = 0 ; i != MAX_ITEMS ; ++i) { if(bind_dp->V[i] != (char*)0) free(bind_dp->V[i]); free(bind_dp->I[i]); if(select_dp->V[i] != (char*)0) free(select_dp->V[i]); free(select_dp->I[i]); } /* 释放绑定描述区和选择描述区 */ SQLSQLDAFree(0 , bind_dp); SQLSQLDAFree(0 , select_dp); } void set_bind_variables() { int i; char bind_var[64]; /* 设置绑定变量最大个数 */ bind_dp->N = MAX_ITEMS; /* 绑定变量名称: 绑定描述区 */ exec sql describe bind variables for s into bind_dp; /* 设置绑定变量实际个数 */ bind_dp->N = bind_dp->F; /* 循环处理绑定变量 */ for(i = 0 ; i != bind_dp->F ; ++i) { /* 显示绑定变量名 */ printf("请输入绑定变量%.*s的值：" , (int)bind_dp->C[i] , bind_dp->S[i]); /* 输入绑定变量的值 */ gets(bind_var); /* 设置绑定变量的长度成员 */ bind_dp->L[i] = strlen(bind_var); /* 为绑定变量数据缓冲区重新分配内存(多一位，留给'\0') */ bind_dp->V[i] = (char*)realloc(bind_dp->V[i] , bind_dp->L[i] + 1); /* 绑定变量数据: 数据缓冲区 */ strcpy(bind_dp->V[i] , bind_var); /* 设置指示变量，处理NULL */ if(0 == strncmp(bind_var , "NULL" , 4) || 0 == strncmp(bind_var , "null" , 4)) *bind_dp->I[i] = -1; else *bind_dp->I[i] = 0; /* 设置数据缓冲区数据类型代码->char */ bind_dp->T[i] = 1; } } void process_select_list() { int i , null_ok , precision , scale; char title[MAX_VNAME_LEN]; /* 设置选择列表项的最大个数 */ select_dp->N = MAX_ITEMS; /* 选择列表项: 选择描述区 */ exec sql describe select list for s into select_dp; /* 设置选择列表项的实际个数 */ select_dp->N = select_dp->F; /* 循环处理选择列表项 */ for(i = 0 ; i != select_dp->F ; ++i) { /* 清除select_dp->T[i]的高位->null */ SQLColumnNullCheck(0 , (unsigned short*)&select_dp->T[i] , (unsigned short*)&select_dp->T[i] , &null_ok); /* 根据内部数据类型确定外部类型数据长度(显示长度) */ switch(select_dp->T[i]) { case 2: /* number类型，取得精度与标度 */ //SQLNumberPrecV6(0 , (unsigned short*)&select_dp->T[i] , &precision , &scale); SQLNumberPrecV6(0 , (unsigned long *)&select_dp->L[i] , &precision , &scale); //wangbaoming modify 201409 if(scale > 0) /* 实数: 显示长度:float */ select_dp->L[i] = sizeof(float); else /* 整数: 显示长度 int */ select_dp->L[i] = sizeof(int); break; case 12: /* DATA数据类型(DD-MON-YY) */ select_dp->L[i] = 9; break; } /* 根据变量长度，重新为选择列表项数据缓冲区分配内存 */ if(2 != select_dp->T[i]) /* 其他类型 */ select_dp->V[i] = (char*)realloc(select_dp->V[i] , select_dp->L[i] + 1); else /* number类型 */ select_dp->V[i] = (char*)realloc(select_dp->V[i] , select_dp->L[i]); /* 初始化title */ memset(title , ' ' , MAX_VNAME_LEN); /* 选择列表项名称: title */ strncpy(title , select_dp->S[i] , select_dp->C[i]); /* 显示列名 */ if(2 == select_dp->T[i]) if(scale > 0) printf("\t%.*s" , select_dp->L[i] + 3, title); else printf("\t%.*s" , select_dp->L[i] , title); else printf("\t%-.*s" , select_dp->L[i] , title); /* 根据Oracle内部类型确定外部数据类型(显示类型) */ if( 2 == select_dp->T[i]) { /* number 类型*/ if(scale > 0) /* float */ select_dp->T[i] = 4; else /* int */ select_dp->T[i] = 3; } else /* char */ select_dp->T[i] = 1; } printf("\n"); /* 提取数据完毕->结束循环 */ exec sql whenever not found do break; /* 循环处理选择列表数据 */ for( ; ; ) { /* 数据->选择描述区 */ exec sql fetch c using descriptor select_dp; /* 显示数据 */ for( i = 0 ; i != select_dp->F ; ++i) { if(*select_dp->I[i] < 0){ /* 处理NULL */ printf("\tNULL"); }else{ if(3 == select_dp->T[i]) { /* int */ printf("\t%d" , *(int*)select_dp->V[i]); }else if(4 == select_dp->T[i]){ /* float */ printf("\t%8.2f" , *(float*)select_dp->V[i]); }else{ /* char */ printf("\t%.*s" , select_dp->L[i] , select_dp->V[i]); } } } printf("\n"); } }