diff options
Diffstat (limited to 'lib/impure/db_mysql.nim')
| -rw-r--r-- | lib/impure/db_mysql.nim | 169 |
1 files changed, 116 insertions, 53 deletions
diff --git a/lib/impure/db_mysql.nim b/lib/impure/db_mysql.nim index 7f7511264..170fee8b8 100644 --- a/lib/impure/db_mysql.nim +++ b/lib/impure/db_mysql.nim @@ -1,7 +1,7 @@ # # # Nim's Runtime Library -# (c) Copyright 2012 Andreas Rumpf +# (c) Copyright 2015 Andreas Rumpf # # See the file "copying.txt", included in this # distribution, for details about the copyright. @@ -43,45 +43,26 @@ import strutils, mysql +import db_common +export db_common + type - DbConn* = PMySQL ## encapsulates a database connection + DbConn* = PMySQL ## encapsulates a database connection Row* = seq[string] ## a row of a dataset. NULL database values will be - ## transformed always to the empty string. - InstantRow* = tuple[row: cstringArray, len: int] ## a handle that can be - ## used to get a row's - ## column text on demand - EDb* = object of IOError ## exception that is raised if a database error occurs - - SqlQuery* = distinct string ## an SQL query string - - FDb* = object of IOEffect ## effect that denotes a database operation - FReadDb* = object of FDb ## effect that denotes a read operation - FWriteDb* = object of FDb ## effect that denotes a write operation -{.deprecated: [TRow: Row, TSqlQuery: SqlQuery, TDbConn: DbConn].} - -proc sql*(query: string): SqlQuery {.noSideEffect, inline.} = - ## constructs a SqlQuery from the string `query`. This is supposed to be - ## used as a raw-string-literal modifier: - ## ``sql"update user set counter = counter + 1"`` - ## - ## If assertions are turned off, it does nothing. If assertions are turned - ## on, later versions will check the string for valid syntax. - result = SqlQuery(query) + ## converted to nil. + InstantRow* = object ## a handle that can be used to get a row's + ## column text on demand + row: cstringArray + len: int +{.deprecated: [TRow: Row, TDbConn: DbConn].} -proc dbError(db: DbConn) {.noreturn.} = - ## raises an EDb exception. - var e: ref EDb +proc dbError*(db: DbConn) {.noreturn.} = + ## raises a DbError exception. + var e: ref DbError new(e) e.msg = $mysql.error(db) raise e -proc dbError*(msg: string) {.noreturn.} = - ## raises an EDb exception with message `msg`. - var e: ref EDb - new(e) - e.msg = msg - raise e - when false: proc dbQueryOpt*(db: DbConn, query: string, args: varargs[string, `$`]) = var stmt = mysql_stmt_init(db) @@ -114,7 +95,7 @@ proc dbFormat(formatstr: SqlQuery, args: varargs[string]): string = add(result, c) proc tryExec*(db: DbConn, query: SqlQuery, args: varargs[string, `$`]): bool {. - tags: [FReadDB, FWriteDb].} = + tags: [ReadDbEffect, WriteDbEffect].} = ## tries to execute the query and returns true if successful, false otherwise. var q = dbFormat(query, args) return mysql.realQuery(db, q, q.len) == 0'i32 @@ -124,7 +105,7 @@ proc rawExec(db: DbConn, query: SqlQuery, args: varargs[string, `$`]) = if mysql.realQuery(db, q, q.len) != 0'i32: dbError(db) proc exec*(db: DbConn, query: SqlQuery, args: varargs[string, `$`]) {. - tags: [FReadDB, FWriteDb].} = + tags: [ReadDbEffect, WriteDbEffect].} = ## executes the query and raises EDB if not successful. var q = dbFormat(query, args) if mysql.realQuery(db, q, q.len) != 0'i32: dbError(db) @@ -139,7 +120,7 @@ proc properFreeResult(sqlres: mysql.PRES, row: cstringArray) = mysql.freeResult(sqlres) iterator fastRows*(db: DbConn, query: SqlQuery, - args: varargs[string, `$`]): Row {.tags: [FReadDB].} = + args: varargs[string, `$`]): Row {.tags: [ReadDbEffect].} = ## executes the query and iterates over the result dataset. ## ## This is very fast, but potentially dangerous. Use this iterator only @@ -167,31 +148,113 @@ iterator fastRows*(db: DbConn, query: SqlQuery, iterator instantRows*(db: DbConn, query: SqlQuery, args: varargs[string, `$`]): InstantRow - {.tags: [FReadDb].} = - ## same as fastRows but returns a handle that can be used to get column text - ## on demand using []. Returned handle is valid only within the interator body. + {.tags: [ReadDbEffect].} = + ## Same as fastRows but returns a handle that can be used to get column text + ## on demand using []. Returned handle is valid only within the iterator body. + rawExec(db, query, args) + var sqlres = mysql.useResult(db) + if sqlres != nil: + let L = int(mysql.numFields(sqlres)) + var row: cstringArray + while true: + row = mysql.fetchRow(sqlres) + if row == nil: break + yield InstantRow(row: row, len: L) + properFreeResult(sqlres, row) + +proc setTypeName(t: var DbType; f: PFIELD) = + shallowCopy(t.name, $f.name) + t.maxReprLen = Natural(f.max_length) + if (NOT_NULL_FLAG and f.flags) != 0: t.notNull = true + case f.ftype + of TYPE_DECIMAL: + t.kind = dbDecimal + of TYPE_TINY: + t.kind = dbInt + t.size = 1 + of TYPE_SHORT: + t.kind = dbInt + t.size = 2 + of TYPE_LONG: + t.kind = dbInt + t.size = 4 + of TYPE_FLOAT: + t.kind = dbFloat + t.size = 4 + of TYPE_DOUBLE: + t.kind = dbFloat + t.size = 8 + of TYPE_NULL: + t.kind = dbNull + of TYPE_TIMESTAMP: + t.kind = dbTimestamp + of TYPE_LONGLONG: + t.kind = dbInt + t.size = 8 + of TYPE_INT24: + t.kind = dbInt + t.size = 3 + of TYPE_DATE: + t.kind = dbDate + of TYPE_TIME: + t.kind = dbTime + of TYPE_DATETIME: + t.kind = dbDatetime + of TYPE_YEAR: + t.kind = dbDate + of TYPE_NEWDATE: + t.kind = dbDate + of TYPE_VARCHAR, TYPE_VAR_STRING, TYPE_STRING: + t.kind = dbVarchar + of TYPE_BIT: + t.kind = dbBit + of TYPE_NEWDECIMAL: + t.kind = dbDecimal + of TYPE_ENUM: t.kind = dbEnum + of TYPE_SET: t.kind = dbSet + of TYPE_TINY_BLOB, TYPE_MEDIUM_BLOB, TYPE_LONG_BLOB, + TYPE_BLOB: t.kind = dbBlob + of TYPE_GEOMETRY: + t.kind = dbGeometry + +proc setColumnInfo(columns: var DbColumns; res: PRES; L: int) = + setLen(columns, L) + for i in 0..<L: + let fp = mysql.fetch_field_direct(res, cint(i)) + setTypeName(columns[i].typ, fp) + columns[i].name = $fp.name + columns[i].tableName = $fp.table + columns[i].primaryKey = (fp.flags and PRI_KEY_FLAG) != 0 + #columns[i].foreignKey = there is no such thing in mysql + +iterator instantRows*(db: DbConn; columns: var DbColumns; query: SqlQuery; + args: varargs[string, `$`]): InstantRow = + ## Same as fastRows but returns a handle that can be used to get column text + ## on demand using []. Returned handle is valid only within the iterator body. rawExec(db, query, args) var sqlres = mysql.useResult(db) if sqlres != nil: let L = int(mysql.numFields(sqlres)) + setColumnInfo(columns, sqlres, L) var row: cstringArray while true: row = mysql.fetchRow(sqlres) if row == nil: break - yield (row: row, len: L) + yield InstantRow(row: row, len: L) properFreeResult(sqlres, row) + proc `[]`*(row: InstantRow, col: int): string {.inline.} = - ## returns text for given column of the row + ## Returns text for given column of the row. $row.row[col] proc len*(row: InstantRow): int {.inline.} = - ## returns number of columns in the row + ## Returns number of columns in the row. row.len proc getRow*(db: DbConn, query: SqlQuery, - args: varargs[string, `$`]): Row {.tags: [FReadDB].} = - ## retrieves a single row. If the query doesn't return any rows, this proc + args: varargs[string, `$`]): Row {.tags: [ReadDbEffect].} = + ## Retrieves a single row. If the query doesn't return any rows, this proc ## will return a Row with empty strings for each column. rawExec(db, query, args) var sqlres = mysql.useResult(db) @@ -209,7 +272,7 @@ proc getRow*(db: DbConn, query: SqlQuery, properFreeResult(sqlres, row) proc getAllRows*(db: DbConn, query: SqlQuery, - args: varargs[string, `$`]): seq[Row] {.tags: [FReadDB].} = + args: varargs[string, `$`]): seq[Row] {.tags: [ReadDbEffect].} = ## executes the query and returns the whole result dataset. result = @[] rawExec(db, query, args) @@ -232,19 +295,19 @@ proc getAllRows*(db: DbConn, query: SqlQuery, mysql.freeResult(sqlres) iterator rows*(db: DbConn, query: SqlQuery, - args: varargs[string, `$`]): Row {.tags: [FReadDB].} = + args: varargs[string, `$`]): Row {.tags: [ReadDbEffect].} = ## same as `fastRows`, but slower and safe. for r in items(getAllRows(db, query, args)): yield r proc getValue*(db: DbConn, query: SqlQuery, - args: varargs[string, `$`]): string {.tags: [FReadDB].} = + args: varargs[string, `$`]): string {.tags: [ReadDbEffect].} = ## executes the query and returns the first column of the first row of the ## result dataset. Returns "" if the dataset contains no rows or the database ## value is NULL. result = getRow(db, query, args)[0] proc tryInsertId*(db: DbConn, query: SqlQuery, - args: varargs[string, `$`]): int64 {.tags: [FWriteDb].} = + args: varargs[string, `$`]): int64 {.tags: [WriteDbEffect].} = ## executes the query (typically "INSERT") and returns the ## generated ID for the row or -1 in case of an error. var q = dbFormat(query, args) @@ -254,7 +317,7 @@ proc tryInsertId*(db: DbConn, query: SqlQuery, result = mysql.insertId(db) proc insertId*(db: DbConn, query: SqlQuery, - args: varargs[string, `$`]): int64 {.tags: [FWriteDb].} = + args: varargs[string, `$`]): int64 {.tags: [WriteDbEffect].} = ## executes the query (typically "INSERT") and returns the ## generated ID for the row. result = tryInsertID(db, query, args) @@ -262,18 +325,18 @@ proc insertId*(db: DbConn, query: SqlQuery, proc execAffectedRows*(db: DbConn, query: SqlQuery, args: varargs[string, `$`]): int64 {. - tags: [FReadDB, FWriteDb].} = + tags: [ReadDbEffect, WriteDbEffect].} = ## runs the query (typically "UPDATE") and returns the ## number of affected rows rawExec(db, query, args) result = mysql.affectedRows(db) -proc close*(db: DbConn) {.tags: [FDb].} = +proc close*(db: DbConn) {.tags: [DbEffect].} = ## closes the database connection. if db != nil: mysql.close(db) proc open*(connection, user, password, database: string): DbConn {. - tags: [FDb].} = + tags: [DbEffect].} = ## opens a database connection. Raises `EDb` if the connection could not ## be established. result = mysql.init(nil) @@ -291,7 +354,7 @@ proc open*(connection, user, password, database: string): DbConn {. dbError(errmsg) proc setEncoding*(connection: DbConn, encoding: string): bool {. - tags: [FDb].} = + tags: [DbEffect].} = ## sets the encoding of a database connection, returns true for ## success, false for failure. result = mysql.set_character_set(connection, encoding) == 0 |